Display device

ABSTRACT

A display device includes: a first closed-bottom lens tube including a first display part on the closed bottom for displaying a first image; a second closed-bottom lens tube including a second display part on the closed bottom for displaying a second image; an adjustment mechanism including a first rod that extends from the first lens tube and a second rod that extends from the second lens tube and is rotatably connected to the first rod; and an image outputter that outputs the first and second images to the first and second display parts, respectively. The image outputter, in accordance with the angle of rotation of the first and second rods of the adjustment mechanism, controls and outputs the first and second images to bring the horizontal directions thereof closer to the arrangement direction of the first and second lens tubes.

CROSS-REFERENCE OF RELATED APPLICATIONS

This application is the U.S. National Phase under 35 U.S.C. § 371 ofInternational Patent Application No. PCT/JP2020/008197, filed on Feb.27, 2020, which in turn claims the benefit of U.S. Application No.62/883,575, filed on Aug. 6, 2019, the entire disclosures of whichApplications are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a display device.

BACKGROUND ART

Recent years have seen extensive development of display devices that areworn on the head, commonly known as head-mounted displays. For example,Patent Literature (PTL) 1 discloses a head-mounted display capable ofpresenting (i.e., displaying) video of content and video of the outsideworld. The head-mounted display disclosed in PTL 1 can reduce the senseof unnaturalness felt by the user upon switching between the video ofcontent and the video of the outside world, by adjusting the luminanceof at least one of the video of content or the video of the outsideworld.

CITATION LIST Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No.2016-090773

SUMMARY OF INVENTION Technical Problem

However, some display devices, including head-mounted displays, may beincapable of displaying images properly.

The present disclosure has been conceived in view of the above problem,and has an object to provide a display device capable of displayingimages properly.

Solution to Problem

In order to achieve the object described above, in one aspect, thedisplay device according to the present disclosure includes: a firstlens tube including a closed bottom and a first display part on theclosed bottom, the first display part being for displaying a firstimage; a second lens tube including a closed bottom and a second displaypart on the closed bottom, the second display part being for displayinga second image; an adjustment mechanism including a first rod thatextends from the first lens tube and a second rod that extends from thesecond lens tube and is rotatably connected to the first rod; and animage outputter that outputs the first image and the second image to thefirst display part and the second display part, respectively. The imageoutputter, in accordance with an angle of rotation of the first rod andthe second rod of the adjustment mechanism, controls and outputs thefirst image and the second image to bring horizontal directions of thefirst image and the second image closer to an arrangement direction ofthe first lens tube and the second lens tube.

Advantageous Effects of Invention

The present disclosure provides a display device capable of displayingimages properly.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a first perspective view of a head-mounted display accordingto the embodiment.

FIG. 1B is a second perspective view of the head-mounted displayaccording to the embodiment.

FIG. 2 is a block diagram illustrating, for example, the head-mounteddisplay according to the embodiment.

FIG. 3 is an external view illustrating the head-mounted displayaccording to the embodiment when worn.

FIG. 4 is a wiring diagram of, for example, signal wires in thehead-mounted display according to the embodiment.

FIG. 5 illustrates a second example of an adjustment mechanism of thehead-mounted display according to the embodiment.

FIG. 6 illustrates a third example of the adjustment mechanism of thehead-mounted display according to the embodiment.

FIG. 7 illustrates a fourth example of the adjustment mechanism of thehead-mounted display according to the embodiment.

FIG. 8 is a first figure for illustrating a problem that occurs when thehead-mounted display is rotated.

FIG. 9A is a first figure for illustrating an image angle maintainer inthe head-mounted display according to the embodiment.

FIG. 9B is a second figure for illustrating the image angle maintainerin the head-mounted display according to the embodiment.

FIG. 9C is a third figure for illustrating the image angle maintainer inthe head-mounted display according to the embodiment.

FIG. 10A is a first figure for illustrating an angle detector in thehead-mounted display according to the embodiment.

FIG. 10B is a second figure for illustrating the angle detector in thehead-mounted display according to the embodiment.

FIG. 10C is a third figure for illustrating the angle detector in thehead-mounted display according to the embodiment.

FIG. 11 is a second figure for illustrating a problem that occurs whenthe head-mounted display is rotated.

FIG. 12 is for illustrating a camera holding mechanism included in thehead-mounted display according to the embodiment.

FIG. 13 is a first figure for illustrating one example of imageadjustment performed by the head-mounted display according to theembodiment.

FIG. 14 is a second figure for illustrating one example of imageadjustment performed by the head-mounted display according to theembodiment.

FIG. 15 is a first figure for illustrating focal correction performed bythe head-mounted display according to the embodiment.

FIG. 16A is a second figure for illustrating focal correction performedby the head-mounted display according to the embodiment.

FIG. 16B is for illustrating image zoom processing that accompaniesfocal correction performed by the head-mounted display according to theembodiment.

FIG. 17 is a first cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 18A is a first perspective view of an eye cup of the head-mounteddisplay according to the embodiment.

FIG. 18B is a top view of the eye cup of the head-mounted displayaccording to the embodiment.

FIG. 18C is a cross sectional diagram of the eye cup taken along lineX-X in FIG. 18A.

FIG. 19A is a first cross sectional diagram of a fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.

FIG. 19B is a second cross sectional diagram of the fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.

FIG. 19C is a third cross sectional diagram of the fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.

FIG. 20 is a second cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 21 is a third cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 22 is a perspective view illustrating the head-mounted displayaccording to the embodiment fitted with a pad.

FIG. 23A is a fourth cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 23B is a second perspective view of the eye cup of the head-mounteddisplay according to the embodiment.

FIG. 24A is a fifth cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 24B is a cross sectional diagram of the eye cup taken along lineZ-Z in FIG. 24A.

FIG. 25A is a sixth cross sectional diagram of the head-mounted displayaccording to the embodiment when worn.

FIG. 25B is a cross sectional diagram of the eye cup taken along lineZ-Z in FIG. 25A.

FIG. 26 is an external view illustrating the eye cup when thehead-mounted display according to the embodiment is worn.

FIG. 27A is a first figure for illustrating a nose piece part in thehead-mounted display according to the embodiment.

FIG. 27B is a second figure for illustrating the nose piece part in thehead-mounted display according to the embodiment.

FIG. 28 is a third figure for illustrating the nose piece part in thehead-mounted display according to the embodiment.

FIG. 29 is a first perspective view illustrating arm parts of thehead-mounted display according to the embodiment.

FIG. 30 is a perspective view illustrating an elastic band of thehead-mounted display according to the embodiment.

FIG. 31 is a second perspective view illustrating arm parts of thehead-mounted display according to the embodiment.

FIG. 32 is a third perspective view illustrating arm parts of thehead-mounted display according to the embodiment.

FIG. 33 is a perspective view illustrating a communication module in thehead-mounted display according to the embodiment.

FIG. 34 is an external view of an arm part of the head-mounted displayaccording to the embodiment when worn.

FIG. 35 is a perspective view illustrating a camera unit of thehead-mounted display according to the embodiment.

FIG. 36A is a block diagram of an image outputter and the like of thehead-mounted display according to the embodiment.

FIG. 36B illustrates an image generator included in the head-mounteddisplay according to the embodiment in greater detail.

FIG. 37 is a first figure for illustrating processes performed by animage generator in the head-mounted display according to the embodiment.

FIG. 38 is for illustrating display processing performed by thehead-mounted display according to the embodiment.

FIG. 39A is for illustrating detection of a point of gaze in thehead-mounted display according to the embodiment.

FIG. 39B is a second figure for illustrating processes performed by theimage generator in the head-mounted display according to the embodiment.

FIG. 40 is a third figure for illustrating processes performed by theimage generator in the head-mounted display according to the embodiment.

DESCRIPTION OF EMBODIMENTS Underlying Knowledge Forming the Basis of thePresent Disclosure

Recent years have seen the development of display devices that a userwears on their head so that the display is arranged in front of theireyes, and allows the user to view an image on a seemingly large screen.Such display devices are referred to as head-mounted displays (HMD).Since these display devices allow the user to view an image on aseemingly large screen through graphical projection perspectivetechniques, the majority have been developed to high specifications anddeveloped to reproduce high-quality images, which results in them havinga large housing. Such large HMDs are not suitable for use in publicspaces such as trains, offices, or outdoor spaces due to theirportability and weight restrictions, as well as their tendency toattract attention.

In view of this, the present disclosure presents a glasses-style HMD,which is a display device, that utilizes two tubular housings(hereinafter also referred to as lens tubes) that minimally cover thetwo displays (display devices) provided for the user's left and righteyes, in order to improve the portability of the HMD. Such aglasses-style HMD is aesthetically pleasing; the wearer appears to bewearing large sunglasses to others, which reduces attention from others,allowing the wearer to blend into his or her surroundings.

There are cases in which the user's two pupils and the two lens tubesare misaligned, inhibiting images from being displayed properly. Thepresent disclosure can freely arrange the two lens tubes to align themwith the positions of the user's pupils and thus properly display theleft and right images by coupling the two lens tubes in a manner thatallows for distance therebetween to be adjusted. One possible method ofimplementing such a coupling that allows for adjustable distance isrotating the lens tubes around a rotational axis positioned away fromthe lens tubes, but with this method, the displays also rotate alongwith the lens tubes. In other words, the rotating of the lens tubescauses the displays that are horizontal in a given reference orientationto slant. The present disclosure is capable of handling such slanting aswell.

HMDs are wearable display devices that are used while worn tightly bythe user so as to keep external light from entering between the displaysand the user's eyes as much as possible in order to eliminate adverseeffects particularly caused by the external light. In other words, theremay be a part of the HMD that contacts the user. The part of the HMDthat contacts the user has a tendency to become unsanitary since theuser's oil or sweat from their skin gets on this part. Since HMDs areused in areas around the eyes in particular where mucous membranes areplentiful, an unsanitary HMD is not suitable for use since there is apossibility of transmission of disease. Cleaning HMDs can be troublesomesince many electronic components are housed inside a small housing. Thepresent disclosure will therefore also discuss a configuration thathandles such a problem.

General and specific aspect(s) of the present disclosure may beimplemented using a system, a method, an integrated circuit, a computerprogram, or a computer-readable recording medium such as a CD-ROM, orany combination thereof.

Hereinafter, an embodiment of the present disclosure will be describedwith reference to the figures.

The following embodiment describes a general or specific example. Thenumerical values, shapes, materials, elements, the arrangement andconnection of the elements, steps, order of the steps, etc., shown inthe following embodiment are mere examples, and therefore do not limitthe scope of the claims. Therefore, among the elements in the followingembodiment, those not recited in any of the independent claims aredescribed as optional elements.

The figures are not necessarily precise illustrations. In the figures,elements that are essentially the same share like reference signs.Accordingly, duplicate description thereof is omitted or simplified.

Moreover, in the present specification, terms that describe arelationship between elements, such as “parallel”, terms that describethe shape of an element, such as “rectangular”, values, and value rangesare not limited to their precise meanings, but also include variationsthat fall within an essentially equivalent range, such as a degree oferror of approximately a few percent.

In each of the drawings described below, the orthogonal X, Y, and Z axesare used to describe, for example, directionality relative to the partsof the HMD. The X axis directions correspond to the right and leftdirections relative to the user when the HMD is worn. Specifically, theleft direction corresponds to the X axis positive direction. The Y axisdirections correspond to the front and back directions relative to theuser when the HMD is worn. Specifically, the back direction correspondsto the Y axis positive direction. The Z axis directions correspond tothe up and down directions relative to the user when the HMD is worn.Specifically, the up direction corresponds to the Z axis positivedirection.

The X axis directions correspond to the directions in which the two lenstubes included in the HMD according to the embodiment are arranged, alsoreferred to as the arrangement direction. This will be described infurther detail later. The Y axis directions correspond to the directionsin which the axes (central axes) of the lens tubes of the HMD extend. APlane passing through the central axes of the two lens tubes is alsoreferred to as an arrangement plane of the lens tubes (or simply“arrangement plane”). The arrangement planes are typically planesparallel to the YX plane. A Z axis direction perpendicular to such anarrangement plane may also be referred to as the height direction.

Hereinafter, the left and right directions, front and back directions,up and down directions, central axis directions, arrangement direction,arrangement plane, and height direction described above may be usedwithout notice in the following description, but these terms are usedfor the sake of convenience in the description, and do not limit theorientation or the like of the HMD when in use.

The majority of components in the HMD according to this embodiment areconfigured in pairs having left/right symmetry. Accordingly, for someconfigurations in the following description, there may be cases in whichone of the left and right components is described and description of theother is omitted.

Embodiment Basic Configuration

First, the configuration of the HMD according to the embodiment will bedescribed with reference to FIG. 1A through FIG. 4. FIG. 1A is a firstperspective view of the head-mounted display according to theembodiment. FIG. 1B is a second perspective view of the head-mounteddisplay according to the embodiment.

FIG. 1A illustrates a perspective view of the external appearance of HMD100 according to the embodiment when first arm part 15 and second armpart 25 are extended, and FIG. 1B illustrates a perspective view of theexternal appearance of HMD 100 according to the embodiment when firstarm part 15 and second arm part 25 are folded.

As illustrated in FIG. 1A, HMD 100 according to the embodiment includesfirst lens tube 10, second lens tube 20, adjustment screw 32, first armpart 15, second arm part 25, first eye cup 14, and second eye cup 24.

First lens tube 10 is a monocular display module for displaying an imagecorresponding to, for example, the left eye of user 99 (see FIG. 3 to bedescribed later). First lens tube 10 is made of a combination of resinand metal materials. First lens tube 10 also includes therewithin afirst display part (included in display part 30 to be described later)for displaying first image 101L (see FIG. 8 to be described later)corresponding to one eye (the left eye in this example) of user 99, andfirst convex lens 40L (see FIG. 13 to be described later) that enlargesthe image displayed by the first display part. More specifically, firstlens tube 10 is a closed-bottom tube, and includes the first displaypart on the bottom thereof.

Even more specifically, first lens tube 10 includes first major part 11,first minor part 12, and first panel 13. As illustrated in the figures,first lens tube 10 has a double bottom structure configured of firstmajor part 11, first minor part 12, and first panel 13. As illustratedin the figures, first major part 11, first minor part 12, and firstpanel 13 are separate components. In the following description, firstlens tube 10 is described as a closed-bottom structure having a doublebottom, but the HMD according to the present disclosure may be aclosed-bottom structure having a single bottom defined by only firstmajor part 11. The structure of the bottom in first lens tube 10 is notparticularly limited; the HMD may be configured of a plurality ofbottoms that respectively house a plurality of functional components.

The first display part and first convex lens 40L are disposed inside thetubular first major part 11 that opens in the Y axis positive direction.Although first convex lens 40L is illustrated as a single lens in thefigures, first convex lens 40L may be configured of a combination of twoor more lenses. Stated differently, first convex lens 40L maybe a lensunit including a plurality of lenses.

Second lens tube 20 is a monocular display module for displaying animage corresponding to, for example, the right eye of user 99. Secondlens tube 20 is made of a combination of resin and metal materials.Second lens tube 20 also includes therewithin a second display part(part of display part 30 to be described later) for displaying secondimage 101R (see FIG. 8 to be described later) corresponding to one eye(the right eye in this example) of user 99, and second convex lens 40R(see FIG. 13 to be described later) that enlarges the image displayed bythe second display part. More specifically, second lens tube 20 is aclosed-bottom tube, and includes the second display part on the bottomthereof.

Even more specifically, second lens tube 20 includes second major part21, second minor part 22, and second panel 23. The second display partand second convex lens 40R are disposed inside the tubular second majorpart 21 that opens in the Y axis positive direction.

First lens tube 10 and second lens tube 20 are coupled together byadjustment screw 32 and connector bar 31.

Connector bar 31 is a bar-shaped component that extends parallel to theX axis. The outer diameter of connector bar 31 is smaller than the innerdiameter of the connection holes formed in the side surfaces of firstlens tube 10 and second lens tube 20. Connector bar 31 is made of a hardmaterial such as metal or resin. This configuration allows connector bar31 to be inserted into the connection holes without requiring anyparticular fixture. The positional relationship between first lens tube10 and second lens tube 20 changes depending on the depth of insertionof connector bar 31 into the connection holes. Although first lens tube10 and second lens tube 20 are exemplified as each including aconnection hole, the connection hole may be provided in only one offirst lens tube 10 and second lens tube 20. In such cases, one end ofconnector bar 31 is inserted into the connection hole and the other endon the opposite side is joined to the other of first lens tube 10 andsecond lens tube 20.

Adjustment screw 32 is a bar-shaped component that forms part of a firstadjustment mechanism, extends parallel to the X axis, and is made of ahard material such as metal or resin. As shown in the cross sectionaldiagram of a cross section taken along the Z-Z line illustrated in thefigures (the diagram in the bubble), screw threads are cut into bothends of adjustment screw 32. More specifically, adjustment screw 32includes, on one end thereof, first screw part 34 configured of firsthelical ridges, and on the other end thereof, second screw part 33configured of second helical ridges.

A hole is formed in first lens tube 10 in a location corresponding toadjustment screw 32, and screw hole 36 configured of first helicalvalleys is formed behind the hole (i.e., on the X axis positivedirection side of the hole). With this configuration, the ridges andvalleys of first screw part 34 and first screw hole 36 engage along agiven length of insertion of adjustment screw 32, and first screw part34 moves inward and outward relative to first screw hole 36 by rotatingadjustment screw 32 around an axis parallel to the X axis. Providing ascrew mechanism behind the hole inhibits first screw part 34 fromprotruding from first lens tube 10 when moving inward and outward, isaesthetically pleasing, and inhibits malfunction of adjustment screw 32caused by the introduction of a foreign substance.

Similarly, a hole is formed in second lens tube 20 in a locationcorresponding to adjustment screw 32, and second screw hole 35configured of second helical valleys is formed behind the hole (i.e., onthe X axis negative direction side of the hole). With thisconfiguration, the ridges and valleys of second screw part 33 and secondscrew hole 35 engage along a given length of insertion of adjustmentscrew 32, and second screw part 33 moves inward and outward relative tosecond screw hole 35 by rotating adjustment screw 32 around an axisparallel to the X axis.

The second helical ridges and valleys are wound in the oppositedirection of the winding of the first helical ridges and valley. Withthis configuration, when adjustment screw 32 is rotated in onedirection, the inward movement of second screw part 33 into second screwhole 35 and the inward movement of first screw part 34 into first screwhole 36 are coordinated and when adjustment screw 32 is rotated in theother direction, the outward movement of second screw part 33 fromsecond screw hole 35 and the outward movement of first screw part 34from first screw hole 36 are coordinated. This adjusts the distancebetween first lens tube 10 and second lens tube 20. In this way,adjustment screw 32 in the first adjustment mechanism is one example ofan operable part that adjusts the distance between first lens tube 10and second lens tube 20.

Note that adjustment screw 32 may be configured to have a central regionthat is thicker than first screw part 34 and second screw part 33. Here,the “center” of adjustment screw 32 refers to the center along the Xaxis when the parts of adjustment screw 32 that connect to first lenstube 10 and second lens tube 20 are placed at both ends. In HMD 100illustrated in FIG. 1A, adjustment screw 32 is configured to have alarger outer diameter in the center than on the X axis ends. Thisconfiguration makes it easier for user 99 to operate adjustment screw33. In the example of the present embodiment, the central region ofadjustment screw 32 (i.e., the X axis central region between first lenstube 10 and second lens tube 20) is given a polygonal pillar shape,which further improves operability by user 99.

The provision of first screw hole 36 and first screw part 34 on theconnection portion of first lens tube 10 and adjustment screw 32 and theprovision of second screw hole 35 and second screw part 33 on theconnection portion of second lens tube 20 and adjustment screw 32 inFIG. 1A is merely one example. For example, first screw hole 36, firstscrew part 34, second screw hole 35, and second screw part 33 may beprovided on one of the connection part of first lens tube 10 andadjustment screw 32 and the connection part of second lens tube 20 andadjustment screw 32, and the other of the connection part of first lenstube 10 and adjustment screw 32 and the connection part of second lenstube 20 and adjustment screw 32 may be configured to simply rotatablyhold and connect with adjustment screw 32.

Furthermore, which of (i) first lens tube 10 and second lens tube 20 or(ii) adjustment screw 32 is provided with the screw hole and which isprovided with the screw part is not particularly limited. For example, aconverse configuration of HMD 100 described above in which first lenstube 10 and second lens tube 20 are provided with screw parts and theadjustment mechanism is provided with screw holes may be used.

Adjusting the distance between first lens tube 10 and second lens tube20 of HMD 100 makes it possible to set the positions of first lens tube10 and second lens tube 20 to correspond to the interpupillary distance(IPD) of user 99.

Moreover, due to connector bar 31 being inserted in the connection hole,rotation of second lens tube 20 relative to first lens tube 10 around anaxis parallel to the X axis when adjusting the distance between firstlens tube 10 and second lens tube 20 can be inhibited, whereby thecentral axes of first lens tube 10 and second lens tube 20 can bemaintained parallel.

The front end of first arm part 15 is connected to first lens tube 10and the rear end engages with, for example, the left ear of user 99.First arm part 15 is made of a combination of metal and resin. First armpart 15 includes first front arm 18 at the front end and first back arm16 at the rear end that are rotatably connected via a hinge shaft. Thehinge shaft is covered by cover 17 that can extend and contract via anaccordion mechanism or the like, and protects internal mechanisms,electronic components, etc.

As illustrated in FIG. 1B, this configuration enables first arm part 15to fold by first back arm 16 rotating and folding relative to firstfront arm 18 around an axis parallel to the Z axis illustrated in thefigure. Moreover, first arm part 15 is only able to fold in thedirection toward second arm part 25 to be described later (fold counterclockwise when viewed from the Z axis positive direction side), and isconfigured so as not to widen in the opposite direction. This makes iteasier for first arm part 15 to engage with the ear of user 99.

The front end of second arm part 25 is connected to second lens tube 20and the rear end engages with, for example, the right ear of user 99.Second arm part 25 is made of a combination of metal and resin. Secondarm part 25 includes second front arm 28 at the front end and secondback arm 26 at the rear end that are rotatably connected via a hingeshaft. The hinge shaft is covered by cover 27 that can extend andcontract via an accordion mechanism or the like, and protects internalmechanisms, electronic components, etc.

As illustrated in FIG. 1B, this configuration enables second arm part 25to fold by second back arm 26 rotating and folding relative to secondfront arm 28 around an axis parallel to the Z axis illustrated in thefigure. Moreover, second arm part 25 is only able to fold in thedirection toward first arm part 15 described above (fold clockwise whenviewed from the Z axis positive direction side), and is configured so asnot to widen in the opposite direction. This makes it easier for secondarm part 25 to engage with the ear of user 99.

As illustrated in FIG. 1A, the rear ends of first arm part 15 and secondarm part 25 curve toward one another. Stated differently, the arm partscurve inward toward the inner space of HMD 100 where the head of user 99goes. This causes first arm part 15 and second arm part 25 to put aninward and forward pressure on the rear part of the head of user 99,which pulls first lens tube 10 and second lens tube 20 closer to andpresses them against the head of user 99. With this configuration, firstarm part 15 and second arm part 25 inhibit HMD 100 from falling off whenworn, improving wearability.

First arm part 15 further includes, on the inner surface of the rearend, first cushion 19 (see FIG. 1B) that presses against the rear partof the head of user 99. Similarly, second arm part 25 further includes,on the inner surface of the rear end, second cushion 29 (see FIG. 1A andFIG. 1B) that presses against the rear part of the head of user 99.These cushions are formed by adhering or applying a material that iselastic, which differs from the hard material that first arm part 15 andsecond arm part 25 are made of. Providing these cushions allow first armpart 15 and second arm part 25 to mitigate the unpleasant feeling feltby user 99 from the pressure of the arm parts.

First eye cup 14 is a tubular component interposed between first lenstube 10 and the head of user 99. First eye cup 14 is detachably attachedto first lens tube 10. For example, when HMD 100 is used by a pluralityof users 99, it is possible to inhibit indirect contact between users 99via first lens tube 10 simply by changing out first eye cup 14.

Moreover, since it is possible to remove and clean first eye cup 14,which is a main component that user 99 comes into contact with, it ispossible to keep HMD 100 sanitary without having to clean the entire HMD100.

Similarly, second eye cup 24 is a tubular component interposed betweensecond lens tube 20 and the head of user 99. Second eye cup 24 isdetachably attached to second lens tube 20. For example, when HMD 100 isused by a plurality of users 99, it is possible to inhibit indirectcontact between users 99 via second lens tube 20 simply by changing outsecond eye cup 24. Moreover, since it is possible to remove and cleansecond eye cup 24, which is a main component that user 99 comes intocontact with, it is possible to keep HMD 100 sanitary without having toclean the entire HMD 100.

First eye cup 14 is attached to first lens tube 10 by being inserted, inthe Y axis negative direction, into first lens tube 10 from the openside of first major part 11. Similarly, second eye cup 24 is attached tosecond lens tube 20 by being inserted, in the Y axis negative direction,into second lens tube 20 from the open side of second major part 21.First eye cup 14 and second eye cup 24 will be further described ingreater detail later.

FIG. 2 is a block diagram illustrating, for example, the head-mounteddisplay according to the embodiment. FIG. 3 is an external viewillustrating the head-mounted display according to the embodiment whenworn. FIG. 4 is a wiring diagram of, for example, signal wires in thehead-mounted display according to the embodiment. In addition to HMD100, FIG. 2 illustrates some external devices and eye 95 of the user.Note that in FIG. 2, elements provided in pairs having left/rightsymmetry, namely first drive circuit 38L and second drive circuit 38R,first display panel 39L and second display panel 39R, and first convexlens 40L and second convex lens 40 are illustrated as drive circuit 38,display panel 39, and convex lens 40 for simplicity.

In HMD 100, power supply 91 and signal processing circuit 92 areconnected via connector 37 and plug 93. Power supply 91 and signalprocessing circuit 92 are external devices connected to HMD 100.

Power supply 91 is a device that supplies power for HMD 100 to carry outvarious operations. For example, power supply 91 is an alternatingcurrent (AC)-direct current (DC) converter that converts householdalternating current power to generate direct current power of a voltagenecessary for HMD 100 to operate. Power supply 91 may be, for example, abattery that discharges stored power as direct current power, or a solarcell that supplies power generated using solar energy. Power supply 91may be provided internally in HMD 100 as a battery, and, alternatively,may be attached to an external surface of HMD 100 as a solar cell. HMD100 may be supplied with power via wireless transmission, without theuse of plug 93 and connector 37.

Signal processing circuit 92 is a device that supplies image informationto HMD 100 via communication. The image information indicates an imageto be displayed. Signal processing circuit 92 supplies the imageinformation as a digital signal, but may supply the image information asan analog signal. Signal processing circuit 92 may also cause HMD 100 tostore the image information and display the image offline when plug 93and connector 37 are disconnected. When online, that is, in a state inwhich the connection of plug 93 and connector 37 is maintained, signalprocessing circuit 92 may supply image information generated in realtime one by one to HMD 100 and cause HMD 100 to display the imageinformation generated in real time. Such image information may besupplied using wireless communication.

As illustrated in FIG. 3, first arm part 15 includes connector 37, whichis for performing at least one of the communication or the power supplydescribed above, in a position behind ear 96L of user 99 when HMD 100 isworn. Providing connector 37 in a position behind ear 96L of user 99inhibits cable 94 connected via plug 93 from entering the field of viewof user 99 and moves the center of gravity of HMD 100 back. Accordingly,arranging connector 37 in this way improves the wearability of HMD 100.

The power and image information supplied from an external device ordevices are transmitted to drive circuit 38 via internal wiring 41. Morespecifically, the image information is transmitted to drive circuit 38via processing unit 38 a as illustrated in FIG. 2. Processing unit 38 ais a processing device that processes the image information to bedisplayed on display part 30 of HMD 100 to convert the image informationinto an analog signal, and performs various image adjustment processes.Processing unit 38 a is implemented as a processor, memory, and aprogram for performing image processes stored in the memory. Theprocesses performed by processing unit 38a, such as the image adjustmentprocesses, will be described in greater detail later.

As illustrated in FIG. 4, the image information supplied to first drivecircuit 38L disposed inside first lens tube 10 via internal wiring 41 infirst arm part 15 is subsequently supplied to second drive circuit 38Rdisposed inside second lens tube 20 via distribution wiring 42. Forexample, as the cross sectional diagram of adjustment screw 32 in FIG. 4illustrates, distribution wiring 42 connects first drive circuit 38L andsecond drive circuit 38R through a hollow space in adjustment screw 32.Forming at least one of adjustment screw 32 or connector bar 31 using ahollow component connects the internal spaces in first lens tube 10 andsecond lens tube 20. Note that the image information may be supplied tosecond drive circuit 38R from first drive circuit 38L by wirelesscommunication.

An image is displayed on display part 30 based on the image informationthat reaches drive circuit 38 in this way as an analog signal. Morespecifically, display panel 39 is driven by drive circuit 38, wherebylight indicating an image is emitted. The light is collected by convexlens 40 and viewed by eye 95 of user 99.

Drive circuit 38 is a circuit device for driving display panel 39.Display panel 39 is a device such as a liquid crystal panel, an organicelectroluminescent (EL) panel, or a micro light-emitting diode (LED)panel. Note that other than display part 30 that uses theabove-described drive circuit 38 and display panel 39, a retinal laserprojector, for example, may be used.

Adjustment Mechanism

Hereinafter, examples of the adjustment mechanism capable of adjustingthe distance between first lens tube 10 second lens tube 20 that differfrom the first adjustment mechanism described in the basic configurationsection above will be given with reference to FIG. 5 through FIG. 7.

FIG. 5 illustrates a second example of the adjustment mechanism of thehead-mounted display according to the embodiment. FIG. 5 illustrates aconfiguration related to a second adjustment mechanism included in HMD100 a according to the embodiment. In particular, FIG. 5 illustrates across sectional diagram related to the second adjustment mechanism inthe bubble. The cross sectional diagram is of a cross section takenalong the Y-Y line illustrated in FIG. 5. Since FIG. 5 is provided fordescribing the second adjustment mechanism that adjusts the distancebetween first lens tube 10 and second lens tube 20, illustrations ofconfigurations other than the second adjustment mechanism, first lenstube 10, and second lens tube 20 are omitted in FIG. 5.

As illustrated in FIG. 5, the second adjustment mechanism is made of acombination of hard materials such as metal and resin. The secondadjustment mechanism includes first rack 54, second rack 55, pinion gear53, adjustment dial 52, and case 51. First rack 54 extends along the Xaxis, has one end connected to first lens tube 10, and includes teeth 54a that project in the Y axis negative direction. Second rack 55 extendsalong the X axis, has one end connected to second lens tube 20, andincludes teeth 55 a that project in the Y axis positive direction.

Pinion gear 53 protrudes radially in an XY plane, includes outer teeth53 a that engage with teeth 54 a and teeth 55 a, and is interposedbetween first rack 54 and second rack 55 in the Y axis directions.

Case 51 holds first rack 54 and second rack 55 so as to be slidablealong the X axis while maintaining the above-described positionalrelationships between first rack 54, second rack 55, and pinion gear 53.Case 51 also holds pinion gear 53 so as to be rotatable around an axisparallel to the Z axis in an orientation that allows outer teeth 53 a tobe engaged with teeth 54 a and teeth 55 a.

Adjustment dial 52 is connected to pinion gear 53 by a shaft (notillustrated) that extends along the rotational axis of pinion gear 53,and rotates along with pinion gear 53 around the axis of the shaft. Inother words, rotating adjustment dial 52 causes pinion gear 53 to rotatein the same direction. When pinion gear 53 rotates, teeth 54 a and 55 aengaged with outer teeth 53 a cause first rack 54 and second rack 55 toslide so as to be fed in directions dependent on the direction ofrotation.

More specifically, when adjustment dial 52 is rotated clockwise from theperspective of the Z axis positive direction side, pinion gear 53rotates clockwise via the shaft, first rack 54 slides in the X axispositive direction and second rack 55 slides in the X axis negativedirection simultaneously. When adjustment dial 52 is rotated counterclockwise from the perspective of the Z axis positive direction side,pinion gear 53 rotates counter clockwise via the shaft, first rack 54slides in the X axis negative direction and second rack 55 slides in theX axis positive direction simultaneously.

The sliding of first rack 54 and second rack 55 causes first lens tube10 and second lens tube 20 connected to the ends thereof to move alongthe X axis, thereby adjusting the distance between first lens tube 10and second lens tube 20. In the second adjustment mechanism, pinion gear53 or adjustment dial 52 that rotates pinion gear 53 corresponds to theoperable part.

Note that first rack 54 or second rack 55 may be provided on one offirst lens tube 10 and second lens tube 20, and one end of case 51 maybe connected to the other of first lens tube 10 and second lens tube 20.In other words, the distance between first lens tube 10 and second lenstube 20 may be adjusted by the one of first lens tube 10 and first lenstube 10 that is connected to first rack 54 or second rack 55 beingcaused to move in a sliding manner by pinion gear 53 relative to theother of first lens tube 10 and second lens tube 20.

FIG. 6 illustrates a third example of the adjustment mechanism of thehead-mounted display according to the embodiment. FIG. 6 illustrates aconfiguration related to a third adjustment mechanism included in HMD100 b according to the embodiment. In particular, FIG. 6 illustrates across sectional diagram related to the third adjustment mechanism in thebubble. The cross sectional diagram is of a cross section taken alongthe Z-Z line illustrated in FIG. 6. Similar to FIG. 5, illustrations ofconfigurations other than the third adjustment mechanism, first lenstube 10, and second lens tube 20 are omitted in FIG. 6.

As illustrated in FIG. 6, the third adjustment mechanism is made of acombination of hard materials such as metal and resin. The thirdadjustment mechanism includes first adjustment hole 63L, secondadjustment hole 63R, adjustment bar 61, first cam lock lever 62L, secondcam lock lever 62R, and anti-slip component 65. First adjustment hole63L is a hole formed along the X axis on the side surface of first lenstube 10, and has an inner diameter that is larger than the outerdiameter of adjustment bar 61 to be described later.

Second adjustment hole 63R is a hole formed along the X axis on the sidesurface of second lens tube 20, and has an inner diameter that is largerthan the outer diameter of adjustment bar 61 to be described later.

Adjustment bar 61 is a bar-shaped component that extends along the Xaxis. Adjustment bar 61 is insertable into first adjustment hole 63L andsecond adjustment hole 63R as a result of the above-describedrelationship with the inner diameters of first adjustment hole 63L andsecond adjustment hole 63R. More specifically, one end of adjustment bar61 is inserted into first adjustment hole 63L, and the other end ofadjustment bar 61 is inserted into second adjustment hole 63R. The otherend of adjustment bar 61 may be directly fixedly connected to the sidesurface of second lens tube 20. In such cases, second adjustment hole63R need not be provided.

As illustrated, first cam lock lever 62L includes a cam mechanism thateccentrically rotates around the axis of rotation of eccentric shaft 64that extends parallel to the Y axis. With this cam mechanism, dependingon the angle of rotation, first cam lock lever 62L presses in the Z axisnegative direction against the one end of adjustment bar 61 insertedinto first adjustment hole 63L. In such a state, adjustment bar 61 ispressed against the Z axis negative side surface in first adjustmenthole 63L. The Z axis negative side surface in first adjustment hole 63Lis provided with anti-slip component 65, and adjustment bar 61 is fixedwhile inserted a given depth in first adjustment hole 63L. In otherwords, first cam lock lever 62L is one example of a lock part. Note thatthe anti-slip component is made using a material having a high frictioncoefficient relative to the material of the Z axis negative side surfaceof adjustment bar 61 (i.e., the surface that contacts anti-slipcomponent 65).

The distance between first lens tube 10 and second lens tube 20 isadjusted by releasing first cam lock lever 62L locked as described aboveand changing the relative positions of adjustment bar 61 and firstadjustment hole 63L. The same applies to second adjustment hole 63R; thedistance between first lens tube 10 and second lens tube 20 is adjustedby releasing locked second cam lock lever 62R and changing the relativepositions of adjustment bar 61 and second adjustment hole 63R. In thethird adjustment mechanism, the distance between first lens tube 10 andsecond lens tube 20 is adjusted mainly by adjustment bar 61.Accordingly, adjustment bar 61 can be regarded as the operable part.

Although FIG. 6 illustrates an example in which first lens tube 10 andsecond lens tube 20 are respectively provided with first adjustment hole63L and second adjustment hole 63R, a configuration is acceptable inwhich only one of first adjustment hole 63L and second adjustment hole63R is provided, and only the one of first cam lock lever 62L and secondcam lock lever 62R that corresponds to the provided adjustment hole isprovided. In such cases, the end of adjustment bar 61 at which the otherof adjustment hole 63L and second adjustment hole 63R and the other offirst cam lock lever 62L and second cam lock lever 62R are not providedis connected to first lens tube 10 or second lens tube 20 via a simpleadhesion or welding technique.

FIG. 7 illustrates a fourth example of the adjustment mechanism of thehead-mounted display according to the embodiment. FIG. 7 illustrates aconfiguration related to a fourth adjustment mechanism included in HMD100 c according to the embodiment. In particular, in the bubble, FIG. 7illustrates front views related to the fourth adjustment mechanism whenHMD 100C is viewed from the Y axis negative direction side. Similar toFIG. 5, illustrations of configurations other than the fourth adjustmentmechanism, first lens tube 10, and second lens tube 20 are omitted inFIG. 7.

As illustrated in FIG. 7, the fourth adjustment mechanism is made of acombination of hard materials such as metal and resin. The fourthadjustment mechanism includes first rod 71, second rod 72, and rotationshaft part 73.

One end of the bar-shaped first rod 71 is connected to first lens tube10 and the other end extends in a direction away from first lens tube 10in an XZ plane. The other end of first rod 71 is connected to rotationshaft part 73 to be described later.

One end of the bar-shaped second rod 72 is connected to second lens tube20 and the other end extends in a direction away from second lens tube20 in a plane parallel to the XZ plane. The other end of second rod 72is connected to rotation shaft part 73 to be described later.

Rotation shaft part 73 is a connection mechanism that rotatably connectsthe other end of first rod 71 and the other end of second rod 72 so asto be rotatable around an axis parallel to the Y axis. First rod 71rotates relative to second rod 72 via rotation shaft part 73 in a planeparallel to the XZ plane. Since the lengths of first rod 71 and secondrod 72 cause the axis of rotation to become eccentric and thus deviateto a position away from first lens tube 10 and second lens tube 20, thedistance between first lens tube 10 and second lens tube 20 is adjustedaccording to the angle of rotation of first rod 71 and second rod 72.For example, in the illustration, the smaller the angle of rotation is,the shorter the distance between first lens tube 10 and second lens tube20 is, and as the angle formed between first rod 71 and second rod 72approaches 180 degrees by rotation, the distance between first lens tube10 and second lens tube 20 increases. In the fourth adjustmentmechanism, the distance between first lens tube 10 and second lens tube20 is adjusted by operating first rod 71 and second rod 72 so as toaround rotation shaft part 73. Accordingly, first rod 71 and second rod72 can be regarded as the operable part.

Image Angle Maintainer

FIG. 8 is a first figure for illustrating a problem that occurs when thehead-mounted display is rotated. FIG. 8 illustrates first image 101Ldisplayed on first display panel 39L and second image 101R displayed onsecond display panel 39R as viewed from the Y axis positive directionside. In FIG. 8, (a) illustrates an HMD according to a comparativeexample in the standard orientation (i.e., an HMD that does not includethe image angle maintainer to be described hereinafter).

With the HMD illustrated in (a) in FIG. 8, first image 101L and image101R are in a state in which the up and down directions of the HMD andthe vertical directions of the images match. In FIG. 8, (b) illustratesthe HMD according to the comparative example when the distance betweenfirst lens tube 10 and second lens tube 20 has been adjusted by firstrod 71, second rod 72, and rotation shaft part 73 described above. Asillustrated in (b) in FIG. 8, the angles of first display panel 39L andsecond display panel 39R rotate along with the rotation of first lenstube 10 and second lens tube 20, and thus there are cases in which theimages cannot be viewed correctly.

HMD 100 c according to this embodiment includes an image anglemaintainer that, in accordance with the angle of rotation of first rod71 and second rod 72, rotates first display panel 39L relative to firstlens tube 10 and rotates second display panel 39R relative to secondlens tube 20 in a direction of rotation opposite that of first displaypanel 39L.

Here, the whole first display part may be rotated so that first drivecircuit 38L also rotates along with first display panel 39L. Firstconvex lens 40L may also be rotated. In such cases, an inner tube may beprovided that rotates relative to first lens tube 10 and holds firstdisplay panel 39L and first convex lens 40L so that the positions ofelements on the optical axis do not change. There may be instances inwhich a freeform lens is used as first convex lens 40L, and in suchcases, when first display panel 39L is rotated relative to first convexlens 40L, the image appears distorted when viewed through first convexlens 40L, so the above configuration is useful in such cases. The abovealso applies to second lens tube 20.

Hereinafter, the image angle maintainer will be described in greaterdetail with reference to FIG. 9A through FIG. 9C. FIG. 9A is a firstfigure for illustrating the image angle maintainer in the head-mounteddisplay according to the embodiment. FIG. 9A through FIG. 9C illustrateHMD 100 c from the perspective of the Y axis negative direction side,and elements other than first display panel 39L, second display panel39R, and the image angle maintainer are illustrated using dashed linesto indicate transparency.

In HMD 100 c illustrated in FIG. 9A, first display panel 39L is providedso as to be rotatable around the central axis of first lens tube 10, andsecond display panel 39R is provided so as to be rotatable around thecentral axis of second lens tube 20. This rotation of first displaypanel 39L and second display panel 39R also applies to FIG. 9B and FIG.9C to be described later.

The image angle maintainer included in HMD 100 c illustrated in FIG. 9Ais implemented as expandable rod 83 including outer tube 81 and innertube 82. Regardless of the distance between first lens tube 10 andsecond lens tube 20 adjusted as a result of inner tube 82 inserted inouter tube 81 expanding and collapsing into the outer tube in directionsparallel to the X axis (expanding and collapsing directions), both endsof expandable rod 83 can be respectively connected to first displaypanel 39L and second display panel 39R.

More specifically, one end of expandable rod 83 is connected to firstdisplay panel 39L while inserted through a hole provided in the sidesurface of first lens tube 10, and the other end of expandable rod 83 isconnected to second display panel 39R while inserted through a holeprovided in the side surface of second lens tube 20.

Connecting first display panel 39L and second display panel 39R via theexpandable rod in this manner makes it possible to maintain the pointsof connection at constant positions relative to the axis of expansionalong which expandable rod 83 expands and collapses. In other words, theend of expandable rod 83 on the inner tube 82 side is connected to firstdisplay panel 39L in a manner that fixes the angle of first displaypanel 39L relative to the axis of expansion, and the end of expandablerod 83 on the outer tube 81 side is connected to second display panel39R in a manner that fixes the angle of second display panel 39Rrelative to the axis of expansion. First lens tube 10 and second lenstube 20 rotate around rotation shaft part 73 which adjusts the distancetherebetween while the angles of first display panel 39L and seconddisplay panel 39R are fixed by the expandable rod 83. With thisoperation, the horizontal directions of first display panel 39L andsecond display panel 39R are approximately parallel to the arrangementdirection of first lens tube 10 and second lens tube 20.

FIG. 9B is a second figure for illustrating the image angle maintainerin the head-mounted display according to the embodiment. The image anglemaintainer included in HMD 100 c illustrated in FIG. 9B includes fixedgear 84, first rotary gear 85, first transfer gears 87, second rotarygear 86 and second transfer gears. Fixed gear 84 is provided on rotationshaft part 73 for obtaining a driving force in the rotation of firstdisplay panel 39L and second display panel 39R.

Fixed gear 84 is independent from the rotation of first rod 71 andsecond rod 72. Stated differently, fixed gear 84 does not rotate alongwith the rotation of first rod 71 and second rod 72. As a result of theangle of fixed gear 84 being maintained, when viewed from theperspective of first rod 71, fixed gear 84 relatively rotates inaccordance with the amount of rotation of first rod 71. Accordingly,fixed gear 84 rotates relatively when also viewed from the perspectiveof first display panel 39L that rotates as first lens tube 10 rotateswith first rod 71. Here, since fixed gear 84 maintains its orientation,fixed gear 84 relatively rotates in the opposite direction of therotation of first rod 71.

First rotary gear 85 rotates along with first display panel 39L. Inother words, by rotating first rotary gear 85, first display panel 39Lrotates in the same direction as first rotary gear 85.

First transfer gears 87 are for transferring the relative rotation offixed gear 84 described above. Here, first transfer gears 87 need totransfer the relative rotation of fixed gear 84 to first rotary gear 85while maintaining the direction of the rotation. Accordingly, an oddnumber of at least one of first transfer gears 87 are provided. As aresult of first rotary gear 85 rotating while the direction of rotationis maintained by first transfer gears 87, first display panel 39Lrotates an amount dependent on the angle of rotation of first rod 71, ina direction opposite the direction of rotation of first rod 71.

The same applies to second rod 72 as well—as a result of the angle offixed gear 84 being maintained, when viewed from the perspective ofsecond rod 72, fixed gear 84 relatively rotates in accordance with theamount of rotation of second rod 72. Accordingly, fixed gear 84 rotatesrelatively when also viewed from the perspective of second display panel39R that rotates as second lens tube 20 rotates with second rod 72.Here, since fixed gear 84 maintains its orientation, fixed gear 84relatively rotates in the opposite direction of the rotation of secondrod 72. Note that the relative rotation of fixed gear 84 when viewedfrom the perspective of second display panel 39R is a rotation in theopposite direction when viewed from the perspective of first displaypanel 39L. In other words, first display panel 39L and second displaypanel 39R rotate in opposite directions.

Second rotary gear 86 rotates along with second display panel 39R. Inother words, by rotating second rotary gear 86, second display panel 39Rrotates in the same direction as second rotary gear 86.

Second transfer gears 88 are for transferring the relative rotation offixed gear 84 described above. Here, second transfer gears 88 need totransfer the relative rotation of fixed gear 84 to second rotary gear 86while maintaining the direction of the rotation. Accordingly, an oddnumber of at least one of second transfer gears 88 are provided. As aresult of second rotary gear 86 rotating while the direction of rotationis maintained by second transfer gears 88, second display panel 39Rrotates an amount dependent on the angle of rotation of second rod 72,in a direction opposite the direction of rotation of second rod 72. Withthis operation, the horizontal directions of first display panel 39L andsecond display panel 39R are approximately parallel to the arrangementdirection of first lens tube 10 and second lens tube 20.

Relative to the rotation of first rod 71 relative to second rod 72,first display panel 39L rotates half the amount and rotates in theopposite direction. Relative to the rotation of second rod 72 relativeto first rod 71, second display panel 39R rotates half the amount androtates in the opposite direction. Here, the number of first transfergears 87 and the number of second transfer gears 88 are the same.Moreover, the gear ratio between fixed gear 84 and first rotary gear 85is 1:1, and the gear ratio between fixed gear 84 and second rotary gear86 is 1:1.

FIG. 9C is a third figure for illustrating the image angle maintainer inthe head-mounted display according to the embodiment. The image anglemaintainer included in HMD 100 c illustrated in FIG. 9C includes stator111, first rotor 112, second rotor 113, first belt 114, and second belt115.

The operations performed by this configuration are the same as describedwith reference to FIG. 9B. In other words, stator 111 operates in thesame manner as fixed gear 84, first rotor 112 operates in the samemanner as first rotary gear 85, second rotor 113 operates in the samemanner as second rotary gear 86, first belt 114 operates in the samemanner as first transfer gears 87, and second belt 115 operates in thesame manner as second transfer gears 88. With this, relative to therotation of first rod 71 relative to second rod 72, first display panel39L rotates half the amount and rotates in the opposite direction.Relative to the rotation of second rod 72 relative to first rod 71,second display panel 39R rotates half the amount and rotates in theopposite direction. With this operation, the horizontal directions offirst display panel 39L and second display panel 39R are approximatelyparallel to the arrangement direction of first lens tube 10 and secondlens tube 20.

Angle Detector

In HMD 100 c according to the embodiment to be described below withreference to FIG. 10A through FIG. 10C, the image displayed on firstdisplay panel 39L and the image displayed on second display panel 39Rare rotated in accordance with the angle of rotation of first rod 71 andsecond rod 72. This configuration produces an HMD 100 c that achievesthe same advantageous effects as those achieved by HMD 100 c thatincludes the image angle maintainer illustrated in FIG. 9A through FIG.9C described above.

More specifically, the inclusion of an angle detector that detects theangle of rotation of first rod 71 and second rod 72 makes it possible torotate displayed images based on the angle of rotation of first rod 71and second rod 72 detected by the angle detector, thereby enabling user99 to correctly view the images.

FIG. 10A is a first figure for illustrating the angle detector in thehead-mounted display according to the embodiment. FIG. 10A through FIG.10C illustrate HMD 100 c from the perspective of the Y axis positivedirection side, and elements other than first display panel 39L, seconddisplay panel 39R, and the angle detector are illustrated using dashedlines to indicate transparency. In each of FIG. 10A through FIG. 10C,images of a person are depicted as first image 101L on first displaypanel 39L and second image 101R on second display panel 39R in thedrawing denoted by (a).

The angle detector included in HMD 100 c illustrated in FIG. 10A detectsthe angle of rotation of first rod 71 and second rod 72 based on theresistance value, measured by a resistance meter or the like, ofresistance element 116 that is included in rotation shaft part 73 andwhose resistance value changes according to the angle of rotation offirst rod 71 and second rod 72.

More specifically, resistance element 116 is implemented as a variableresistor. A variable resistor is an electronic component whoseresistance value changes according to an amount of rotation of a knobrelative to the base. In other words, by fixedly disposing the baserelative to first rod 71 and fixedly disposing the knob relative tosecond rod 72, the knob rotates relative to the base in conjunction withthe rotation of first rod 71 and second rod 72. Then, the amount ofrotation of the knob relative to the base, that is to say, the amount ofrotation (angle of rotation) of second rod 72 relative to first rod 71is detected by measuring the resistance value. The amount of rotation isan amount of difference calculated by subtracting reference orientationθ1 from θ2 illustrated in FIG. 10A.

Image outputter 38 b (see FIG. 36A to be described later) (1) performs afirst process of generating first rotated image 102L by changing thedisplay angle of first image 101L corresponding to one eye of user 99and (2) performs a second process of generating second rotated image102R by changing the display angle of second image 101R corresponding tothe other eye of user 99. In the generation of these rotated images,image outputter 38 b, for example, performs coordinate conversionprocessing that overwrites the luminance value of each pixel with aluminance value of a coordinate-converted position, by performingaddress conversion on the input image, and generates the rotated imagesthat display the luminance values of the pixels at the convertedcoordinates. The amount of rotation of the images is half the amount ofdifference. Regarding the direction of rotation of the images, the imagedisplayed on first display panel 39L is rotated in the oppositedirection that first rod 71 rotates relative to second rod 72, and theimage displayed on second display panel 39R is rotated in the oppositedirection that second rod 72 rotates relative to first rod 71. With thisprocess, the images are rotated such that the horizontal directions offirst image 101L and second image 101R are approximately parallel to thearrangement direction of first lens tube 10 and second lens tube 20.

FIG. 10B is a second figure for illustrating the angle detector in thehead-mounted display according to the embodiment. The angle detectorincluded in HMD 100 c illustrated in FIG. 10B includes first gyrosensor117 and second gyrosensor 118.

First gyrosensor 117 is provided in or on first lens tube 10, detectshow much it is tilting, and outputs amount of tilt 83. Second gyrosensor118 is provided in or on second lens tube 20, detects how much it istilting, and outputs amount of tilt 84. The amount of rotation of firstrod 71 and second rod 72 is obtained by adding the absolute values ofthe output 83 and 84. Since subsequent image processes are the same asthe processes described above with reference to FIG. 10A, repeateddescription thereof will be omitted.

FIG. 10C is a third figure for illustrating the angle detector in thehead-mounted display according to the embodiment. The angle detectorincluded in HMD 100 c illustrated in FIG. 10C obtains the distancebetween first lens tube 10 and second lens tube 20 from firstmeasurement device 121 and second measurement device 122. For example,first measurement device 121 and second measurement device 122 measurethe distance between first lens tube 10 and second lens tube 20 andoutput the result of the measurement. Note that this configuration canbe implemented so long as one of first measurement device 121 and secondmeasurement device 122 is provided. Accordingly, both first measurementdevice 121 and second measurement device 122 need not be provided.

The angle of rotation can be calculated by a trigonometric functionusing the distance between first lens tube 10 and second lens tube 20and the distance between the center of rotation shaft part 73 and thecenter of first lens tube 10. In other words, the angle detectorcalculates half the angle formed between first rod 71 and second rod 72by the inverse sine function from the distance between the center ofrotation shaft part 73 and the center of first lens tube 10 relative tohalf the distance between first lens tube 10 and second lens tube 20.The angle detector performs the same calculation before and after arotation to detect the angle corresponding to the angle of rotationchanged by the rotation. Since subsequent image processes are the sameas the processes described above with reference to FIG. 10A, repeateddescription thereof will be omitted.

Next, another problem caused by the rotation of first rod 71 and secondrod 72 and how the problem is handled will be described with referenceto FIG. 11 and FIG. 12. FIG. 11 is a second figure for illustrating aproblem that occurs when the head-mounted display is rotated. FIG. 12 isfor illustrating a camera holding mechanism included in the head-mounteddisplay according to the embodiment.

FIG. 11 and FIG. 12 illustrate HMD 100 c from the perspective of the Yaxis negative direction side, and elements other than first camera 123L,second camera 123R, and the camera holding mechanism are illustratedusing dashed lines to indicate transparency. First camera 123L isprovided inside first minor part 12 and captures images in a forwarddirection through first panel 13. Second camera 123R is provided insidesecond minor part 22 and captures images in a forward direction throughsecond panel 23. First panel 13 and second panel 23 may be half mirrors.This allows for the cameras to be hidden when viewed from the outsideand thus images can be captured without drawing attention from people inthe surrounding area.

Although first camera 123L and second camera 123R are positioned in thecentral regions of first lens tube 10 and second lens tube 20 along theZ axis in the examples in FIG. 11 and FIG. 12, the positions of firstcamera 123L and second camera 123R are not limited to this example.First camera 123L and second camera 123R may be fixedly provided tofirst lens tube 10 and second lens tube 20 so as to capture images inthe Y axis negative direction. For example, as illustrated in FIG. 17 tobe described later, first camera 123L and second camera 123R may bedisposed in the spaces formed inside first minor part 12 and secondmajor part 22, on the Z axis negative side ends of the spaces, and,alternatively, may be disposed on the Z axis positive side ends of thespaces, which is not illustrated in FIG. 17. More preferably, firstcamera 123L and second camera 123R are positioned in the central regionsof first lens tube 10 and second lens tube 20 along the Z axis, in frontof eyes 95 of user 99.

First camera 123L that captures images in a direction parallel to thecentral axis of first lens tube 10 and opposite the direction in whichfirst lens tube 10 opens (i.e., in the forward direction) is provided inor on first lens tube 10. Second camera 123R that captures images in adirection parallel to the central axis of second lens tube 20 andopposite the direction in which second lens tube 20 opens (i.e., in theforward direction) is provided in or on second lens tube 20. Firstcamera 123L and second camera 123R are used in a video see-through modethat displays video captured outside of HMD 100 c as images. If theorientations of first camera 123L and second camera 123R are notmaintained as illustrated in FIG. 11 when first lens tube 10 and secondlens tube 20 rotate, video cannot be displayed suitably.

There are instances in which first camera 123L and second camera 123Rare used to measure the distance from HMD 100 c to an object captured bythe cameras. Since the distance is measured using triangulation, thedistance between first camera 123L and second camera 123R needs to beknown in advance.

For example, for the former, just like with the rotation of the imagesdescribed above, it is possible to rotate the video captured by anamount dependent on the angle of rotation, and for the latter, it ispossible to separately measure the distance between the first lens tube10 and second lens tube 20 and correct the distances.

HMD 100 c according to this embodiment includes a camera holdingmechanism separate from the camera holding mechanism described above.This camera holding mechanism holds first camera 123L and second camera123R so as to maintain the distance therebetween at a given distance,and fixes the orientations of first camera 123L and second camera 123R.More specifically, as illustrated in FIG. 12, this camera holdingmechanism includes fixing panel 126 that fixes the orientations of anddistance between first camera 123L and second camera 123R, holding panel125 that maintains the position of fixing panel 126 with rotation shaftpart 73 as a reference, and shaft support 124 that maintains theposition of holding panel 125 relative to rotation shaft part 73 at agiven position.

Shaft support 124 is provided on rotation shaft part 73, and fixes the Xaxis position of holding panel 125 relative to the rotation shaft part.However, shaft support 124 is capable of moving along the Z axis in anelongated hole provided in holding panel 125. In other words, X axismovement of holding panel 125 is fixed relative to rotation shaft part73, and holding panel 125 can freely move along the Z axis. Moreover,the positional relationship between holding panel 125 and fixing panel126 is fixed.

First camera 123L and second camera 123R can freely move along the Xaxis in first lens tube 10 and second lens tube 20, and can freelyrotate relative to first lens tube 10 and second lens tube 20. Withthis, the X axis positions and angles of first camera 123L and secondcamera 123R are fixed by holding panel 125 and fixing panel 126.Accordingly, HMD 100 c can suitably capture and display video, andmeasure the distance to an object correctly displayed.

Note that since first camera 123L and second camera 123R arerespectively provided on first minor part 12 and second minor part 22,fixing panel 126 is fixed to holding panel 125 in a location further inthe Y axis negative direction than first major part 11 and second majorpart 21, and in a location further in the Y axis positive direction thanfirst panel 13 and second panel 23.

As described above, this camera holding mechanism is provided for thepurpose of adjusting the distance between first camera 123L and secondcamera 123R. In other words, this camera holding mechanism is useful innot only HMD 100 c in which first camera and second camera rotate withthe rotational movement of other parts, but also in any of the HMDscapable of adjusting the distance between first lens tube 10 and secondlens tube 20 in accordance with the IPD of user 99. Accordingly, HMD100, HMD 100 a, and HMD 100 b may be implemented to include the samecamera holding mechanism as described above.

Next, image processing according to the IPD of user 99 will be describedwith reference to FIG. 13 and FIG. 14. FIG. 13 is a first figure forillustrating one example of image adjustment performed by thehead-mounted display according to the embodiment. FIG. 14 is a secondfigure for illustrating one example of image adjustment performed by thehead-mounted display according to the embodiment. In FIG. 13 and FIG.14, (a) illustrates the configuration of part of the HMD when viewedfrom above user 99, and (b) illustrates first display panel 39L andsecond display panel 39R from the perspective of user 99.

FIG. 13 illustrates a case in which the IPD of user 99 matches thedistance between the centers of first convex lens 40L and second convexlens 40R. FIG. 14 illustrates a case in which display positions ofimages displayed on the display surfaces of first display panel 39L andsecond display panel 39R have been adjusted to match the IPD of user 99.As illustrated in FIG. 13, when the IPD of user 99 matches the distancebetween the centers of first convex lens 40L and second convex lens 40R,first image 101L and image 101R are displayed in the centers of firstdisplay panel 39L and second display panel 39R, respectively. Moreover,images displayed like in (b) in FIG. 13 are deformed into rounded imagesby passing through the convex lenses to generate the correct images.

In contrast, in the example illustrated in FIG. 14, the displaypositions of images on first display panel 39L and second display panel39R have been adjusted to match the IPD of user 99. Here, the refractionof first convex lens 40L and second convex lens 40R produces distortionthat increases outward. Accordingly, with HMD 100 illustrated in FIG.14, deformation to cancel the distortion is applied to the images beforebeing displayed on first display panel 39L and second display panel 39R.In particular, as illustrated in (b) in FIG. 14, the part of thedisplayed image in the region of the convex lens outside the dashed-linecircle, which corresponds to the periphery of the convex lens wheredistortion is readily observed, is greatly deformed in accordance withthe great amount of distortion. This distortion is applied by imageoutputter 38 b.

In other words, image outputter 38 b performs distortion correctionprocessing of correcting the lens distortion of first convex lens 40Laccording to the position of image 101L displayed on first display panel39L relative to the center of first display panel 39L and correcting thelens distortion of second convex lens 40R according to the position ofimage 101R displayed on second display panel 39R relative to the centerof second display panel 39R. In the distortion correction processing,image outputter 38 b adjusts, in accordance with the position of image101L relative to the center of first display panel 39L, image 101R to bedisplayed on second display panel 39R so as to be symmetrical on the Zaxis and antisymmetrical on the X axis relative to the center of seconddisplay panel 39R.

FIG. 15 is a first figure for illustrating focal correction performed bythe head-mounted display according to the embodiment. FIG. 16A is asecond figure for illustrating focal correction performed by thehead-mounted display according to the embodiment. FIG. 16B is forillustrating image zoom processing that accompanies the focal correctionperformed by the head-mounted display according to the embodiment.

In HMD 100 according to this embodiment, focal correction is performedby adjusting, in accordance with material about user 99, the distancebetween first convex lens 40L and first display panel 39L and thedistance between second convex lens 40R and second display panel 39R.For example, as illustrated in FIG. 15, HMD 100 displays an image thatmatches the focal point of user 99 by adjusting the Y axis position ofdisplay panel 39 (i.e., one of first display panel 39L and seconddisplay panel 39R).

Moreover, for example, as illustrated in FIG. 16A, HMD 100 adjusts thefocal point of user 99 to the position of display panel 39 by adjustingthe Y axis position of convex lens 40 (i.e., one of first convex lens40L and second convex lens 40R). Here, the angle of view (black arrowsin the figure) changes as the distance between convex lens 40 and eye 95changes. Image outputter 38 b performs zoom processing that enlarges orshrinks the display size of the image to be displayed on display panel39 to a size dependent on the angle of view.

For example, when the angle of view decreases like in (a) in FIG. 16A,image outputter 38 b generates and displays an enlarged image 101 a asshown in (a) in FIG. 16B. Since (b) in FIG. 16A and (b) in FIG. 16Billustrate the display of a normal image 101 corresponding to a normalangle of view, description will be omitted. For example, when the angleof view increases like in (c) in FIG. 16A, image outputter 38 bgenerates and displays a shrunk image 101 b as shown in (c) in FIG. 16B

Eye Cup

Next, the configuration of the eye cup according to this embodiment willbe described with reference to FIG. 17 through FIG. 26. FIG. 17 is afirst cross sectional diagram of the head-mounted display according tothe embodiment when worn. FIG. 17 illustrates a cross sectional diagramin the YZ plane passing through first lens tube 10, and user 99. Asillustrated in FIG. 17, first eye cup 14 inhibits direct contact betweenuser 99 and first lens tube 10. First eye cup 14 is configured to coverone eye of the user, and as the cross sectional diagram shows, first eyecup 14 is interposed between user 99 and first lens tube 10 at twovisual points on the brow side and the cheek side.

In this way, first eye cup 14 is configured to fill in the space betweenuser 99 and first lens tube 10. First eye cup 14 is made using amaterial that is capable of elastically deforming, such as siliconrubber, and has a light blocking characteristic. First eye cup 14 may bemade using a sponge-like resin material. As a result of first eye cup 14having a light blocking characteristic and being configured to fill inthe space between user 99 and first lens tube 10, HMD 100 inhibits areduction in visibility resulting from light emitted for the purpose ofshowing user 99 an image and external light mixing.

FIG. 18A is a first perspective view of the eye cup of the head-mounteddisplay according to the embodiment. FIG. 18B is a top view of the eyecup of the head-mounted display according to the embodiment. FIG. 18C isa cross sectional diagram of the eye cup taken along line X-X in FIG.18A.

As illustrated in FIG. 18A through FIG. 18C, first eye cup 14 accordingto this embodiment includes tubular first insertion part 14 a that isinserted in, in particular, first major part 11 of first lens tube 10,and curved-sheet-shaped first cup part 14 b that extends outward fromthe open end of first major part 11 (i.e., extends in the Y axispositive direction) and is sized to reach the head of user 99 when user99 is wearing HMD 100. First cup part 14 b curves along the curve ofuser 99 from the surrounding area of eye 95 to the side of the head. Asurface is formed on the contact end of first cup part 14 b thatcontacts user 99 so as to increase the surface area of contact. Here,first cup part 14 b continuously covers the space between theabove-described curved contact end that follows the curve of the head ofuser 99 and the connection end that is connected to first insertion part14 a. With this configuration, first cup part 14 b functions to connectthe separated first lens tube 10 and the head of user 99 to blockexternal light from entering the field of view of user 99.

First narrow part 14 c is formed between first insertion part 14 a andfirst cup part 14 b and has a smaller outer circumference than the outercircumference of first insertion part 14 a and the outer circumferenceof first cup part 14 b. Stated differently, first narrow part 14 c is athin-walled portion that is formed around the entire circumference ofthe outer surface of first eye cup 14. The formation of first narrowpart 14 c gives first eye cup 14 flexibility in the up, down, left, andright directions. Here, the flexibility of first eye cup 14 in the upand down directions is useful as it improves wearability for user 99without affecting the left/right parallax of HMD 100, but there areinstances where the flexibility of first eye cup 14 in the left andright directions affects the left/right parallax of HMD 100.

In view of this, first eye cup 14 includes first thick part 14 d at anintersection of first narrow part 14 c and a line parallel to thearrangement direction that passes through the center of the narrow partin the height direction (i.e., at an intersection of first narrow partfirst narrow 14 c and the arrangement plane) that expands outward beyondthe outer circumference. First thick part 14 d is integrally formed withfirst eye cup 14 so as to fill in first narrow part 14 c in thearrangement plane. First thick part 14 d has a tapered shape so as towiden in diameter in the Y axis negative direction of first lens tube10.

With this, first cup part 14 b presses first thick part 14 d at thesmaller diameter end in the Y axis negative direction, and the forceexerted by the pressing is supported by the other larger diameter end.In other words, the fulcrum is small and definite, and first thick part14 d functions to facilitate deflection of first cup part 14 b in adirection away from the fulcrum. As a result, first cup part 14 b caneasily deflect in the up and down directions.

First thick part 14 d supports first cup part 14 b from the firstinsertion part 14 a side so as to oppose left and right deflection offirst eye cup 14. In order to further strengthen the support of firstcup part 14 b, first cup part 14 b includes first plate part 14 e thatis connected to the first cup part and extends outward beyond firstthick part 14 d in an XZ plane that intersects the central axis of firstlens tube 10. This forms a structure like a seesaw whereby thedeflection of first eye cup 14 is supported by first plate part 14 e,whereby deflection in the left and right directions is stronglyinhibited and deflection in the up and down directions can easily occurin a state in which the shape of first cup part 14 b is maintained.

Moreover, as illustrated in FIG. 18C, first major part 11 and firstinsertion part 14 a are connected (or fitted) by the engagement of arecessed and protruded structure. This configuration will be describedwith reference to FIG. 19A through FIG. 19C. First support ring 127illustrated in FIG. 18C will also be described later.

FIG. 19A is a first cross sectional diagram of the fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.FIG. 19B is a second cross sectional diagram of the fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.FIG. 19C is a third cross sectional diagram of the fitting mechanism ofthe eye cup of the head-mounted display according to the embodiment.

FIG. 19A through FIG. 19C illustrate cross sectional diagrams taken inthe XY plane of first lens tube 10 and first eye cup 14 from theperspective of the Z axis positive direction side. In FIG. 19A, firstmajor part 11 includes first protruding part 132 that is formed on theinner surface and protrudes inward. Moreover, when fitted, first eye cup14 forms first recessed part 14 f at a location on first insertion part14 a that corresponds to first protruding part 132. First eye cup 14 isinhibited from falling off from first major part 11 by first recessedpart 14 f and first protruding part engaging when inserted so that firstrecessed part 14 f covers the first protruding part.

As illustrated in FIG. 19B, first protruding part 132 may be formed onthe distal end of first extension part 131 that extends from the innersurface of first major part 11 toward the central axis. Since thedirection in which first protruding part 132 protrudes is parallel tothe Y axis, first eye cup 14 is easily fitted.

However, with only first protruding part 132 illustrated in FIG. 19B,although the fitting of first eye cup 14 becomes easier, the possibilitythat first eye cup 14 will fall off increases. In view of this, asillustrated in FIG. 19C, first protruding part 132 may include firstprojecting part 133 that extends from the tip end of first protrudingpart 132 toward the inner surface of first major part 11. With thisconfiguration, first eye cup 14 that can easily fall off in the Y axisdirection in the structure illustrated in FIG. 19B is latched by firstprojecting part 133 in this variation, which inhibits first eye cup 14from falling off.

First correction lens 134 that adjusts the focal length of first convexlens 40L may be provided between first eye cup 14 and first convex lens40L. FIG. 20 is a second cross sectional diagram of the head-mounteddisplay according to the embodiment when worn.

As illustrated in FIG. 20, when implementing the configuration describedabove, first eye cup 14 is used to fix first correction lens 134 inplace. More specifically, first support ring 127 is provided on firstmajor part, at a location that is closer to the bottom of first majorpart 11 than first insertion part 14 a is and closer to the opening offirst major part 11 than first convex lens 40L is. First support ring127 is fixed to the inner surface of first major part 11, and is notremovable like first eye cup 14 is.

When first eye cup 14 is fitted as described above in a state in whichfirst correction lens 134 is disposed closer to the opening than firstsupport ring 127 is, first correction lens 134 is sandwiched by firstsupport ring 127 and first insertion part 14 a of first eye cup 14. Thisresults in first correction lens 134 being attached inside of first lenstube 10.

First correction lens 134 can be detached from first major part 11 bydetaching first eye cup 14. Accordingly, even when a single HMD 100 isused by both a user 99 that does not need first correction lens 134 anda user 99 that needs the first correction lens, first correction lens134 can be selectively placed in or removed when exchanging or removingand cleaning first eye cup 14.

FIG. 21 is a third cross sectional diagram of the head-mounted displayaccording to the embodiment when worn. As illustrated in FIG. 21, in astate in which first eye cup 14 is removed, HMD 100 can be worn whileuser 99 is wearing a corrective device such as glasses 135, on top ofglasses 135 or the like. For example, glasses 135 are pressed against byfirst support ring 127 and a second support ring not illustrated in thefigure and held so as not to contact first convex lens 40L and secondconvex lens 40R.

FIG. 22 is a perspective view illustrating the head-mounted displayaccording to the embodiment fitted with a pad. As illustrated in FIG.22, HMD 100 is provided with pad 136 when first eye cup 14 is removedfrom HMD 100 and HMD 100 is to be used by a user 99 who does not wearglasses 135 or the like. Pad 136 can be fitted to the top portion of HMD100 in the height direction, and is interposed between HMD 100 and thebrow of user 99. Pad 136 is made using, for example, the same siliconrubber that is used for first eye cup 14. FIG. 22 illustrates an examplein which pad 136 is attached to connector bar

Like first eye cup 14 and second eye cup 24, pad 136 also has theadvantage of being able to keep HMD 100 sanitary, by inhibiting directcontact by being interposed between the brow of user 99 and first andsecond lens tubes 10 and 20.

However, unlike first eye cup 14 and the second eye cup, since pad 136does not cover eyes 95 of user 99, it is difficult to block theperipheral vision of user 99. For example, when images captured by firstcamera 123L and second camera 123R are displayed using first displaypanel 39L and second display panel 39R, if first eye cups 14 are fitted,user 99 only takes in visual information corresponding to the angle ofview of the camera. This is because the peripheral vision is blocked;stated differently, there are instances in which objects approachinguser 99 from the side cannot be visually detected by user 99. Forexample, when fitted in instances like described above, pad 136 isfavorable because the peripheral vision is not blocked.

The eye cup may have a dual structure in which the configuration of thetop and the configuration of the bottom are different. FIG. 23A is afourth cross sectional diagram of the head-mounted display according tothe embodiment when worn. FIG. 23B is a second perspective view of theeye cup of the head-mounted display according to the embodiment.

As illustrated in FIG. 23A and FIG. 23B, first eye cup 147 that isfitted in place of first eye cup 14 is configured of first upper cuppart 146 disposed on the top and first lower cup part 145 disposed onthe bottom. As indicated by the arrows in the figures, first upper cuppart 146 is thicker than first lower cup part 145. With thisconfiguration, first upper cup part 146 has a larger surface area ofcontact with the head of user 99 than first lower cup part 145.Moreover, first upper cup part 146 is made using a harder material thanfirst lower cup part 145. For example, the material used for first uppercup part 146 is silicon rubber. For example, the material used for firstlower cup part 145 is a sponge-like resin material. However, the eye cupmay be formed using a single material, and two different hardnesses maybe achieved by altering the filling density of the material.

Using first eye cup 147 configured in this way makes it possible tofocus the pressing force exerted onto the head of user 99 when HMD 100is worn at first upper cup part 146. First upper cup part 146corresponds to the brow of user 99 and the first lower cup partcorresponds to the cheek of user 99. Impression or marks from wearingHMD 100 are more visible on the cheeks than on the brow. Pressure on thecheeks is uncomfortable to user 99, and furthermore, since the cheeksare relatively soft, it is difficult to stabilize HMD 100. First eye cup147 can focus the pressure exerted when HMD 100 is worn at first uppercup part 146 to overcome these problems.

Close-Contact Mechanism

Next, a close-contact mechanism that improves the fit of HMD 100 usingfirst eye cup 14 will be described. FIG. 24A is a fifth cross sectionaldiagram of the head-mounted display according to the embodiment whenworn. FIG. 24B is a cross sectional diagram of the eye cup taken alongline Z-Z in FIG. 24A.

HMD 100 according to this embodiment negatively pressurizes the spaceformed between first eye cup 14, first convex lens 40L, and eye 95L ofuser 99 to bring first lens tube 10 into close contact with the head ofuser 99 by suction. Accordingly, as illustrated in (a) in FIG. 24A, HMD100 includes: pressure reduction port part 137 located inside the space;pressure reduction tube 138 that is, for example, located inside firstarm part 15 and in fluid communication with pressure reduction port part137; and electric pump 139 a. As illustrated in (b) in FIG. 24A, handpump 139 b may be used instead of electric pump 139 a to achieve anequivalent configuration.

When electric pump 139 a is driven, air is pulled out through pressurereduction tube 138. As illustrated in FIG. 24B, pressure reduction portpart 137 includes openings in fluid communication with the space formedbetween first eye cup 14, first convex lens 40L, and eye 95L of user 99.The air in the space is pulled out through the openings. This forms anegative pressure space, which suctions HMD 100 to the head of user 99.

First major part 11 is provided with pressure valve 142 to preventexcessive negative pressure. Pressure valve 142 allows HMD 100 to besuctioned at a suitable negative pressure, and forms a flow of air frompressure valve 142 to the negative pressure space, and from the negativepressure space to the electric pump.

Evaporated moisture from sweat from the head of user 99 begins to fillthe space that is approximately air tight due to the suction of HMD 100.Since the moisture can fog first convex lens 40L, it is necessary toinhibit the moisture in order to display images properly. For example,the air flow described above exchanges out the air containing theevaporated moisture and reduces fogging.

Moreover, for example, HMD 100 includes cooling device 141 that coolsthe negative pressure air from outside first eye cup 14. For example,cooling device 141 is implemented using a Peltier device.

Moreover, for example, HMD 100 includes heating device 143 that heatsfirst convex lens 40L. For example, heating device 143 is implementedusing a heating pipe, and transfers heat generated by first displaypanel 39L and first drive circuit 38L and the like along the pipe tofirst convex lens 40L.

Moreover, if first eye cup 14 is made of a material that absorbsmoisture, vaporized moisture in the air is absorbed by first eye cup 14.FIG. 25A is a sixth cross sectional diagram of the head-mounted displayaccording to the embodiment when worn. FIG. 25B is a cross sectionaldiagram of the eye cup taken along line Z-Z in FIG. 25A.

First eye cup 144 illustrated in FIG. 25A and FIG. 25B is made of thesame material as the above-described absorbent first eye cup 14, andthus absorbs vaporized moisture in the air. Unlike the configurationdescribed with reference to FIG. 24A and FIG. 24B, pressure reductiontube 138 in this configuration is in fluid communication with first eyecup 144. A tube forming a loop along the tubular shape of first eye cup144 is formed in first eye cup 144, and pressure reduction tube 138pulls air from the entire circumference of first eye cup 144. Absorbedmoisture can be pulled along with the air, whereby the absorbency offirst eye cup 144 can be maintained for a long period of time.

When HMD 100 is configured to be brought into close contact with user 99by suction like in FIG. 24A through FIG. 25B, the suctioning effect canbe further increased by increasing the surface area of contact betweenthe eye cup and the head of user 99. FIG. 26 is an external viewillustrating the eye cup when the head-mounted display according to theembodiment is worn.

As illustrated in FIG. 26, by using first eye cup 148 including a largerfirst cup part than the first cup part that is included in first eye cup14, more of the head of user 99 can be covered, thereby increasing thesurface area of contact between first eye cup 148 and the head of user99.

Nose Piece Part

HMD 100 according to this embodiment includes a nose piece part thatsupports HMD 100 on the nasal root of user 99 to keep HMD 100 fromslipping. FIG. 27A is a first figure for illustrating the nose piecepart in the head-mounted display according to the embodiment. FIG. 27Bis a second figure for illustrating the nose piece part in thehead-mounted display according to the embodiment. FIG. 28 is a thirdfigure for illustrating the nose piece part in the head-mounted displayaccording to the embodiment.

As illustrated in FIG. 27A through FIG. 28, the nose piece part includesnose pad 152, mounting part 151, and a coupling part. Nose pad 152 is acomponent having a curved surface that contacts the nasal root of user99, and reduces how heavy HMD 100 feels by dispersing the load of HMD100 placed on the nasal root.

Mounting part 151 is a component that is mounted to an element locatedclose the center of gravity of HMD 100 between first lens tube 10 andsecond lens tube 20, such as connector bar 31, adjustment mechanism 32,case 51, adjustment bar 61, expandable rod 83, and/or fixing panel 126.The shape of mounting part 151 is designed according to the shape of theelement or elements to which it is to be attached.

The coupling part is a component that couples nose pad 152 and mountingpart 151 at a given distance and a given angle that are defined by theposition of the nasal root of user 99. For example, as illustrated inFIG. 27A, the coupling part includes: plate component 153 that iscoupled to mounting part 151 and includes coupling hole 153 a; rodcomponent 154 that has a leading end coupled to nose pad 152 and isinserted through coupling hole 153 a; and fixing component 155 thatfixes the length of rod component 154 that is inserted into couplinghole 153 a.

User 99 selects a plate component 153 in which coupling hole 153 a isformed in an appropriate Z axis position, and fixes rod component 154 atan appropriate insertion length using fixing component 155 to adjust theposition of nose pad 152 in a YZ plane.

Moreover, as illustrated in FIG. 27B and FIG. 28, the coupling part maybe a plate-shaped deformable component 156 that is formed using amaterial capable of plastic deformation by an outside force. Examples ofsuitable materials for such a coupling part include a metal or compositemetal such as iron, aluminum, tin, and stainless steel, as well as aresin capable of plastic deformation. Here, “deformation” excludesruptures, breaks, and fractures and the like, and refers to a change inshape that allows for the positional relationship between mounting part151 and nose pad 152 to be maintained even after deforming.

Arm Part

Next, the configuration of an arm part according to this embodiment willbe described. First arm part 15 and second arm part 25 have the samebasic configurations as described above, and are components whose endsin the Y axis positive direction engage on the ears of the user.

The arm part may be a component that is exchangeable for another armpart suitable for user 99 or suitable for the application of HMD 100. Inother words, first arm part 15 and second arm part 25 are attachable anddetachable, and are exchangeable by attaching or detaching another armpart. Although the attachment mechanism of first arm part 15 and secondarm part 25 is not illustrated in the figures in particular, any sort ofmechanism may be implemented, such as a mechanism where a part fits in ahole, engagement that takes into account direction of gravitationalforce, magnetic coupling, coupling via some other attachment component,etc. When connector 37 and internal wiring 41 described above providedin and/or on first arm part 15, when first lens tube 10 and first armpart 15 are connected, in the area of the connection, there are aplurality of points of connection so that internal wiring 41 and thewiring provided in first lens tube 10 are connected.

FIG. 29 is a first perspective view illustrating the arm parts of thehead-mounted display according to the embodiment. For example, asillustrated in FIG. 29, the Z axis positions of first lens tube 10 andsecond lens tube 20 relative to first arm part 15 and second arm part 25may be adjustable via the positional relationship between the eyes andears of user 99. FIG. 29 illustrates first arm part 15 and second armpart 25 which are in the standard positions, first arm part 15 a andsecond arm part 25 a which are connected below the standard positions,and first arm part 15 b and second arm part 25 b which are connectedeven further below.

FIG. 30 is a perspective view illustrating an elastic band of thehead-mounted display according to the embodiment. For example, whenthere is a chance that HMD 100 may fall off user 99 with only theengagement of the arm parts on the ears alone, such as when HMD 100 isexpected to be used in situations that involve intense movement, elasticband 157 may be fitted in place of the arm parts, as illustrated in FIG.30.

FIG. 31 is a second perspective view illustrating the arm parts of thehead-mounted display according to the embodiment. For example, when HMD100 is used by a user 99 whose head is larger than first arm part 15 andsecond arm part 25 can accommodate, first arm part 15 c and second armpart 25 c that widen along the X axis may be fitted, as illustrated inFIG. 31.

FIG. 32 is a third perspective view illustrating the arm parts of thehead-mounted display according to the embodiment. For example, converseto the configuration in FIG. 31, when HMD 100 is used by a user 99 whosehead is smaller than first arm part 15 and second arm part 25 canaccommodate, first arm part 15 d and second arm part 25 d that are moresharply curved may be fitted, as illustrated in FIG. 32.

FIG. 33 is a perspective view illustrating a communication module in thehead-mounted display according to the embodiment. As illustrated in FIG.33, some elements of a communication module related to wirelesscommunication performed by HMD 100 are provided in first arm part 15 andsecond arm part 25. Specifically, the communication module includesfirst antenna 161, second antenna 162, first wiring 163, second wiring164, receiver 165, and signal processing processor 166. Among theseelements, first antenna 161 is provided inside first arm part 15, andsecond antenna 162 is provided inside second arm part 25.

Providing the elongated first antenna 161 and second antenna 162 in theelongated first arm part 15 and second arm part 25 is both aestheticallypleasing and inhibits a reduction in the size of the elements. Radiowaves detected by first antenna 161 are received by receiver 165 viafirst wiring 163, and converted into data by signal processing processor166. Similarly, radio waves detected by second antenna 162 are receivedby receiver 165 via second wiring 164, and converted into data by signalprocessing processor 166. Note that the frequency of the signalsreceived by first antenna 161 and second antenna 162 may be different.In other words, the length of first antenna 161 and the length of secondantenna 162 may differ.

FIG. 34 is an external view of the arm part of the head-mounted displayaccording to the embodiment when worn. As illustrated in FIG. 34, forexample, arm part 175 may, in addition to function as an arm part, beconnected to the head-mounted display to inhibit the head-mounteddisplay from falling off. Arm part 175 includes front part 171, rearpart 172, return spring 173, and ear hook 174. Front part 171 is formedso as to be able to slide into tubular rear part 172, and front part 171and rear part 172 are pulled together by return spring 173. Ear hook 174is provided on rear part 172. Front part 171 connected to first lenstube 10 simultaneously pulls rear part 172 forward and pulls ear hook174 forward via return spring 173. Since this causes ear hook 174 toengage with the ear of user 99, HMD 100 can be stably worn via asuitable amount of bias. Note that arm part 175 configured in the samemanner is also connected on the second lens tube side.

FIG. 35 is a perspective view illustrating a camera unit of thehead-mounted display according to the embodiment. As illustrated in FIG.35, HMD 100 includes, in addition to first camera 123L and second camera123R, first side camera 181L, second side camera 181R, first rear camera182L, and second rear camera 182R.

For example, when using HMD 100 in the video see-through mode describedabove, images captured in lateral directions by first side camera 181Land second side camera 181R are displayed, and images captured in arearward direction by first rear camera 182L and second rear camera 182Rare displayed. Depending on the situation, as illustrated in the figure,shade 183 may be attached that, for example, blocks or attenuates partof the light incident on first camera 123L and second camera 123R.

Image Outputter

Images are viewed by user 99 as a result of HMD 100 according to thisembodiment displaying the images using first display panel 39L andsecond display panel 39R HMD 100. The images are displayed by firstdisplay panel 39L and second display panel 39R after the angles andpositions of the images, distortion caused by convex lenses 40, and zoomprocessing and the like are adjusted, corrected, and performed asdescribed above by image outputter 38 b.

In addition to adjusting the orientations of images to suit HMD 100configured in such a manner, image outputter 38 b may correct the imagesin accordance with the visual capability of user 99 and the applicationof HMD 100. Hereinafter, correction of images by HMD 100 according tothis embodiment will be described. FIG. 36A is a block diagram of animage outputter and the like of the head-mounted display according tothe embodiment. FIG. 36B illustrates an image generator included in thehead-mounted display according to the embodiment in greater detail.

As illustrated in FIG. 36A, processing unit 38 a in HMD 100 includesimage obtainer 191, image content estimator 192, color temperaturedeterminer 193, luminance detector 194, output luminance determiner 195,orientation adjuster 196, image generator 197, and mode receiver 198.Each of these is implemented by a program for realizing the functionsassigned to the functional blocks being executed by the processor andmemory of processing unit 38 a.

Image obtainer 191 is a functional block for obtaining images to bedisplayed on first display panel 39L and second display panel 39R. Imageobtainer 191 obtains images from external signal processing circuit 92.Image obtainer 191 also obtains images from first camera 123L, secondcamera 123R, first side camera 181L, second side camera 181R, first rearcamera 182L, second rear camera 182R, and image capturing device 94,which is an external camera or the like. Images obtained by imageobtainer 191 are transmitted to orientation adjuster 196, image contentestimator 192, and luminance detector 194.

As described above, orientation adjuster 196 is a functional block thatperforms processes such as the above-described adjustment of the angleand position of the images, correction of distortion caused by convexlenses 40, and the zoom processing. Orientation information foradjusting the orientation of the images is output as a result of theprocessing performed by orientation adjuster 196.

Image content estimator 192 is a functional block for estimating thecontent of obtained images. Estimating image content is, for example,estimating whether the subject of an image captured by image capturingdevice 94 is any one of candidates including a food, a person, a pieceof art, scenery, etc. When the captured image is video such as movingimages, estimating image content may be estimating the genre of thevideo, such as whether the video is a documentary, a drama, animation,news, sports, etc. Image content estimator 192 transmits contentinformation indicating the image content to color temperature determiner193 and output luminance determiner 195.

Luminance detector 194 is a functional block that detects the luminanceof obtained images. The detection of luminance includes one or more ofdetection of the highest luminance value, detection of the lowestluminance value, detection of the average luminance value, and thedetection of the median luminance value. The detected luminance istransmitted to output luminance determiner 195.

Color temperature determiner 193 is a functional block that determinesthe color temperature of the images to be displayed on first displaypanel 39L and the second display panel based on the content informationreceived from image content estimator 192. For example, when the contentinformation indicates food, i.e., that the user is eating food, theimages are adjusted to a color temperature that makes the food appearmore appetizing (for example, a color temperature corresponding to6500K, which matches natural daylight). Color temperature determiner 193determines the color temperature of the image to be displayed on firstdisplay panel 39L based on such processing.

Output luminance determiner 195 is a functional block that determinesthe luminance of the images to be displayed on first display panel 39Land the second display panel based on the content information receivedfrom the image content estimator 192 and the luminance detected by theluminance detector. For example, when the content information indicatesfood, i.e., that the user is eating food, output luminance determiner195 sets the lowest detected luminance value to an output value of 0,and sets the highest detected luminance value to the maximum outputvalue.

In this example, mode receiver 198 is a functional block that receives achange of the operation mode of HMD 100 by user 99 from, for example, aninput terminal such as a smartphone, tablet, or personal computer (PC),or an operation panel (not illustrated in the drawings) provided on HMD100. Mode information dependent on the operation mode of HMD 100received by mode receiver 198 is input into color temperature determiner193 and output luminance determiner 195.

Examples of HMD operation modes include, in addition to a night mode, amorning mode, a relax mode, etc., a cataracts mode and a colorcorrection mode that are used when user 99 has cataracts or a colorvision deficiency, which mitigate the symptoms.

In the morning mode, color temperature determiner 193 and outputluminance determiner 195 perform correction that increases the colortemperature and the luminance. In the night mode and the relax mode,color temperature determiner 193 and output luminance determiner 195perform correction that decreases the color temperature and theluminance.

In the cataracts mode, output luminance determiner 195 corrects theluminance so that the black colors appear blacker. FIG. 37 is a firstfigure for illustrating processes performed by the image generator ofthe head-mounted display according to the embodiment. FIG. 37illustrates luminance levels of output light relative to the luminancelevels of input light when the cataracts mode described above is used.

As illustrated in (a) in FIG. 37, compared to the normal input/outputrelationship indicated by the dotted and dashed line, correction isperformed to make the black colors at the low level end appear blackerby reducing the level overall. As illustrated in (b) in FIG. 37,correction that incrementally makes the black colors closer to black byadjusting the gradation characteristic may be performed. As illustratedin (c) in FIG. 37, only the black colors may be corrected to be blacker,and the levels of white colors at the high level end may be maintained.As illustrated in (d) in FIG. 37, correction that maintains the averageluminance level by blackening by suppressing the black and white colorsand increasing the brightness of the levels between the black and whitecolors may be performed.

Moreover, in the adjustment of the images, when display part 30 isconfigured to include a backlight for, for example, a liquid crystalpanel, the luminance of the backlight may be adjusted. FIG. 38 is forillustrating display processing performed by the head-mounted displayaccording to the embodiment. FIG. 38 illustrates the relationshipbetween backlight luminance relative to input level. The black colorsmay be adjusted to appear blacker when displayed by dimming thebacklight.

When this sort of adjustment is performed across the entire displaypanel 39, user 99 may find that the images appear unnatural. Therefore,the correction may be bypassed at the point of gaze of user 99 and thecorrection may increase in strength with increasing distance from thepoint of gaze. FIG. 39A is for illustrating detection of a point of gazein the head-mounted display according to the embodiment. FIG. 39B is asecond figure for illustrating processes performed by the imagegenerator of the head-mounted display according to the embodiment.

As illustrated in FIG. 39A, HMD 100 includes light source 200 andphotoreceptor 199 for detecting the point of gaze of user 99. With this,the correction of the level is performed incrementally in accordancewith distance from the point of gaze, as illustrated in FIG. 39B.

Returning to FIG. 36A, in the color correction mode, images havingcolors that appear more natural to user 99 can be displayed bysuppressing colors other than those that are difficult for user 99 tosee. In the color correction mode, when the crystalline lenses of theeyes of user 99 have changed to a yellow color causing user 99 to vieweverything with a yellow tint, images having colors that appear morenatural to allow user 99 can be displayed by suppressing yellow colors.

FIG. 40 is a third figure for illustrating processes performed by theimage generator of the head-mounted display according to the embodiment.FIG. 40 illustrates luminance levels of output light relative toluminance levels of input light, just like FIG. 37. For example, whenHMD 100 is used in an environment in which objects are difficult to see,such as in heavy fog, heavy rain, or at night, correction that improvesvisibility may be performed. As illustrated in (a) in FIG. 40,correction that increases contrast may be performed by defining maximumand minimum luminances for the input level, and outputting valuesoutside of the range defined thereby at a constant level.

When reducing the overall luminance, such as in the night mode,correction that incrementally reduces intermediate values withoutchanging the maximum and minimum luminance values may be performed, asillustrated in (b) in FIG. 40.

As illustrated in (c) in FIG. 40, depending on the detected averageluminance, the output level may be corrected so as to match the averageluminance of the equivalent level.

Referring back to FIG. 36A, image generator 197 displays an image ondisplay part 30 that satisfies the orientation, color temperature, andluminance determined as described above. As illustrated in FIG. 36B,image generator 197, for example, obtains an image whose orientation hasbeen adjusted, and in order to adjust the color temperature andluminance, performs gain adjustment by multiplying correction values forthe red, blue, and green values. An image generated in this manner isoutput to drive circuit 38, whereby an appropriate image is displayed ondisplay panel 39 by the drive circuit.

Advantageous Effects, etc.

As described above, HMD 100 c according to this embodiment includes: aclosed-bottom first lens tube 10 including first display panel 39L onthe closed bottom for displaying first image 101L; a closed-bottomsecond lens tube 20 including second display panel 39R on the closedbottom for displaying second image 101R; a fourth adjustment mechanismincluding first rod 71 that extends from first lens tube 10 and secondrod 72 that extends from second lens tube 20 and is rotatably connectedto first rod 10; and image outputter 38 b that outputs first image 101Land second image 101R to first display panel 39L and second displaypanel 39R, respectively. Image outputter 38 b, in accordance with anangle of rotation of first rod 71 and second rod 72 of the fourthadjustment mechanism, controls and outputs first image 101L and secondimage 101R to bring horizontal directions of first image 101L and secondimage 101R closer to an arrangement direction of first lens tube 10 andsecond lens tube 20.

With this configuration, when second rod 72 is rotated relative to firstrod 71, the orientation of the images from the perspective of user 99can be maintained by rotating the images displayed by first displaypanel 39L and second display panel 39R. Accordingly, HMD 100 c canproperly display images.

Moreover, for example, HMD 100 according to this embodiment may includea closed-bottomed first lens tube 10 including first display panel 39Lon the closed bottom for displaying first image 101L; a closed-bottomedsecond lens tube 20 including second display panel 39R on the closedbottom for displaying second image 101R; and a first adjustmentmechanism that couples first lens tube 10 and second lens tube 20 and iscapable of adjusting the distance between first lens tube 10 and secondlens tube 20. The first adjustment mechanism may include an operablepart that adjusts the distance between first lens tube 10 and secondlens tube 20.

With this configuration, since the distance between first lens tube 10and second lens tube 20 is adjustable via the adjustment mechanism, eventhrough first lens tube 10 and second lens tube 20 are provided as twolens tubes, it is possible to display images in an orientation thatsuits user 99. Accordingly, HMD 100 can properly display images.

Moreover, for example, the adjustment mechanism may include: screw hole35 or 36 formed in one of first lens tube 10 and second lens tube 20;and as the operable part, adjustment screw 32 having one end on whichscrew part 33 or 34 that screws into screw hole 35 or 36 is formed andanother end that is connected to the other of first lens tube 10 andsecond lens tube 20, and the adjustment mechanism may adjust thedistance between first lens tube 10 and second lens tube 20 byadjustment of a depth that screw part 33 or 34 is screwed into screwhole 35 or 36.

With this configuration, the distance between first lens tube 10 andsecond lens tube 20 is adjustable by simply rotating adjustment screw 32owing to the relationship between the screw and the screw ridges.Accordingly, HMD 100 can easily properly display images.

Moreover, for example, the first adjustment mechanism may include: firstscrew hole 36 formed in first lens tube 10; second screw hole 35 formedin second lens tube 20; and, as the operable part, adjustment screw 32including, on respective ends, first screw part 34 that screws intofirst screw hole 36 and second screw part 33 that screws into secondscrew hole 35. Adjustment screw 32 may be connected to first lens tube10 and second lens tube 20 via the respective ends. The first adjustmentmechanism may adjust the distance between first lens tube 10 and secondlens tube 20 by adjustment of a depth that first screw part 34 isscrewed into first screw hole 36 and a depth that second screw part 33is screwed into second screw hole 35.

With this configuration, the distance between first lens tube 10 andsecond lens tube 20 is adjustable by simply rotating adjustment screw 32owing to the relationship between the screw and the screw ridges. It ispossible to quickly adjust the distance between first lens tube 10 andsecond lens tube 20, owing to the adjustment of the depth that firstscrew part 34 is screwed into first screw hole 36 and the adjustment ofthe depth that second screw part 33 is screwed into second screw hole35. Accordingly, HMD 100 can easily properly display images.

Moreover, for example, second screw hole 35 may include a helicalstructure wound in an opposite direction than the helical structure offirst screw hole 36.

With this configuration, the depth that first screw part 34 is screwedinto first screw hole 36 and the depth that second screw part is screwedinto second screw hole 35 can be adjusted simultaneously, simply byrotating adjustment screw 32 in one direction, owing to the relationshipbetween the screw and the screw ridges. Accordingly, HMD 100 can easilyproperly display images.

Moreover, for example, the outer diameter of the center of adjustmentscrew 32 may be larger than the outer diameter of at least one of endsof adjustment screw 32.

This configuration improves the operability of adjustment screw 32 whenadjusting the distance between first lens tube 10 and second lens tube20. Accordingly, HMD 100 can easily properly display images.

Moreover, for example, the second adjustment mechanism may include:elongated first and second racks 54 and 55 each having an end connectedto a respective one of first lens tube 10 and second lens tube 20 andrespectively including teeth 54 a and 55 a; pinion gear 53 includingouter teeth 53 a that engage with teeth 54 a and 55 a; and case 51 thatslidably holds first rack 54 and second rack 55 rotatably holds piniongear 53 in an orientation that allows outer teeth 53 a to engage withteeth 54 a and 55 a.

With this configuration, the distance between first lens tube 10 andsecond lens tube 20 is adjustable by simply rotating pinion gear 53.Accordingly, HMD 100 a can easily properly display images.

Moreover, for example, the third adjustment mechanism may include:adjustment hole 63L or 63R formed in the side surface of at least one offirst lens tube 10 or second lens tube 20; adjustment bar 61 connectedto the other of first lens tube 10 and second lens tube 20 and havingone end connected via insertion into adjustment hole 63L or 63R; andfirst lock bar 62L or second lock bar 62R that fixes adjustment bar 61and adjustment hole 63L or 63R. The distance between first lens tube 10and second lens tube 20 may be adjusted by changing the relativepositions of adjustment hole 63L or 63R and adjustment bar 61 byunlocking first lock bar 62L or second lock bar 62R.

With this configuration, it is possible to adjust the distance betweenfirst lens tube 10 and second lens tube 20 simply by adjusting the depthof insertion of adjustment bar 61 into adjustment hole 63L or 63R.Accordingly, HMD 100 b can easily properly display images.

Moreover, for example, the fourth adjustment mechanism may include firstrod 71 that has one end connected to first lens tube 10 and anotherother end that extends in a direction away from first lens tube 10;second rod 72 that has one end connected to second lens tube 20 andanother end that extends in a direction away from second lens tube 20;and rotation shaft part 73 that rotatably connects first rod 71 andsecond rod 72.

With this configuration, the distance between first lens tube 10 andsecond lens tube 20 is adjustable by simply second rod 72 relative tofirst rod 71. Accordingly, HMD 100 c can easily properly display images.

Moreover, for example, HMD 100 may further include a connection partincluding a connection hole formed in the side surface of at least oneof first lens tube 10 or second lens tube 20 and bar-shaped connectorbar 31 having a smaller outer diameter than the inner diameter of theconnection hole, and first lens tube 10 and second lens tube 20 may beconnected via the connection part.

With this configuration, it is possible for adjustment screw 32 and theconnection part to keep the central axis of first lens tube 10 and thecentral axis of second lens tube 20 parallel to one another. The centralaxes will not twist even if the distance between first lens tube 10 andsecond lens tube 20 is adjusted. Accordingly, HMD 100 can easilyproperly display images.

Moreover, for example, HMD 100 may further include a nose piece partthat contacts nasal root 97 of user 99 wearing HMD 100. The nose piecepart may include nose pad 152 that contacts nasal root 97 of user 99,mounting part 151 mounted to at least one of adjustment screw 32 or theconnection part, and a coupling part that couples nose pad 152 andmounting part 151 at a given distance and a given angle. The couplingpart may be made using a material capable of deformation by an outsideforce.

With this configuration, it is possible to support HMD 100 with nasalroot 97 as well, thereby further stabilizing the orientation of HMD 100.Accordingly, wobbling of HMD 100 can be inhibited, and HMD 100 canproperly display images.

Moreover, for example, HMD 100 may further include a nose piece partthat contacts nasal root 97 of user 99 wearing HMD 100. The nose piecepart may include nose pad 152 that contacts nasal root 97 of user 99,mounting part 151 mounted to at least one of adjustment screw 32 and theconnection part, and a coupling part that couples nose pad 152 andmounting part 151 at a given distance and a given angle. The couplingpart may include plate component 153 that is coupled to mounting part151 and includes coupling hole 153 a, rod component 154 that has aleading end coupled to nose pad 152 and is inserted through couplinghole 153 a; and fixing component 155 that fixes the length of rodcomponent 154 that is inserted into coupling hole 153 a.

With this configuration, it is possible to support HMD 100 with nasalroot 97 as well, thereby further stabilizing the orientation of HMD 100.Accordingly, wobbling of HMD 100 can be inhibited, and HMD 100 canproperly display images.

Moreover, for example, HMD 100 may further include first arm part 15 andsecond arm part 25 each having one end that is connected to a respectiveone of first lens tube 10 and second lens tube 20 and the other end thatextends to engage on the top of an ear of user 99.

With this configuration, user 99 can wear HMD 100 by engaging first armpart 15 and second arm part 25 on their ears. This improves the ease ofuse of HMD 100.

Moreover, for example, each of first arm part 15 and second arm part 25may be detachable at the one end that is connected to first lens tube 10or second lens tube 20.

With this configuration, first arm part 15 and second arm part 25 can bedetached. For example, when different shaped arm parts are available, itis possible to exchange out the arm parts depending on application, forexample. This broadens the applications that HMD 100 can be used in.

Moreover, for example, each of first arm part 15 and second arm part 25may be curved inward at the other end opposite the one end that isconnected to first lens tube 10 or second lens tube 20.

With this configuration, since the head of user 99 is held by first armpart 15 and second arm part 25 by compression, and first lens tube 10and second lens tube 20 are pulled from the back of the head, theorientation of HMD 100 is more stable. Accordingly, wobbling of HMD 100can be inhibited, and HMD 100 can properly display images.

Moreover, for example, at least one of first arm part 15 or second armpart 25 may include connector 37 to which cable 94 for at least one ofcommunication or charging is connected. Connector 37 may be providedbehind an ear of user 99 when HMD 100 is worn.

With this configuration, cable 94 is less likely to enter the field ofview of user 99, reducing annoyance when using HMD 100. Moreover, sincethe weight of cable 94 places the center of gravity of HMD 100 furtherback, the positions of first lens tube 10 and second lens tube 20 arestable. Accordingly, wobbling of HMD 100 can be inhibited, and HMD 100can properly display images.

Moreover, for example, HMD 100 may further include image outputter 38 bthat adjusts display positions of images to be displayed on firstdisplay panel 39L and second display panel 39R. Image outputter 38 b mayadjust the position of the image to be displayed on second display panel39R so as to be symmetrical about the height direction andantisymmetrical about the arrangement direction relative to the centerof second display panel 39R, in accordance with the position of theimage to be displayed on first display panel 39L relative to the centerof first display panel 39L.

With this configuration, it is possible to adjust the display positionsof images based on the positions of both eyes of user 99. Accordingly,HMD 100 can properly display images.

Moreover, for example, image outputter 38 b may perform distortioncorrection processing of correcting the lens distortion of first convexlens 40L according to the position of the image to be displayed on firstdisplay panel 39L relative to the center of first display panel 39L andcorrecting the lens distortion of second convex lens 40R according tothe position of the image to be displayed on second display panel 39Rrelative to the center of second display panel 39R.

This configuration allows HMD 100 to properly display images regardlessof lens distortion.

Moreover, for example, focal correction corresponding to the eyesight ofuser 99 may be performed by adjusting the distance between first convexlens 40L and first display panel 39L and adjusting the distance betweensecond convex lens 40R and second display panel 39R, and image outputter38 b may perform zoom processing of changing the display size of theimage to be displayed on first display panel 39L and the image to bedisplayed on second display panel 39R in accordance with the focalcorrection.

This configuration allows HMD 100 to properly display images regardlessof changes in angle of view brought on by adjustments to opticalsystems.

Moreover, for example, HMD 100 may include: a closed-bottomed first lenstube 10 including first display panel 39L on the closed bottom fordisplaying first image 101L; a closed-bottomed second lens tube 20including second display panel 39R on the closed bottom for displayingsecond image 101R; an adjustment mechanism including an operable partbetween first lens tube 10 and second lens tube 20 that adjusts adistance between first lens tube 10 and second lens tube 20; and firsteye cup 14 and second eye cup 24 respectively provided for first lenstube 10 and second lens tube 20 that are tubular and detachably attachedto the open end of first lens tube 10 and second lens tube 20. First eyecup 14 and second eye cup 24 may include: insertion part 14 a and thelike that is tubular and inserted inside first lens tube 10 or secondlens tube 20; and cup part 14 b and the like having a curved sheet shapethat extends outside of first lens tube 10 or second lens tube 20.

With this configuration, first eye cup 14 and second eye cup 24 areinterposed between the head of user 99 and first and second lens tubes10 and 20, thereby keeping first lens tube 10 and second lens tube 20sanitary. Since first eye cup 14 and second eye cup 24 can be detached,they can be replaced or cleaned, which allows for HMD 100 to be usedcleanly over a long period of time. Accordingly, HMD 100 is difficult tobecome unsanitary, and thus suitable for use.

Moreover, for example, insertion part 14 a, etc., includes recessed part14 f, etc., corresponding to protruding part 132, etc., formed on theinside of the tube, and cup part 14 b, etc., may block external light bycontinuously covering the space between a contact end contoured to matchthe head of a person and a connection end that is connected to insertionpart 14 a, etc.

With this configuration, first eye cup 14 and second eye cup 24 can beeasily connected and disconnected via engagement between a recessed andprotruded structure. Accordingly, changing out first eye cup 14 andsecond eye cup 24 is less complex. Accordingly, HMD 100 can be keptsanitary easily, is difficult to become insanitary, and is suitable foruse. Moreover, since the space between the head of user 99 and firstlens tube 10 and second lens tube 20 is continuously covered, it ispossible to maintain high light blocking characteristics. Accordingly,since the space inside HMD 100 can be darkened, the images can bedisplayed more clearly, and HMD 100 can properly display images.

Moreover, for example, protruding part 132, etc., may extend toward theopen end of first lens tube 10 or second lens tube 20 from the end ofextension part 131, etc., that extends from the inner wall surface onthe inside of first lens tube 10 or second lens tube 20 toward thecentral axis of first lens tube 10 or second lens tube 20, and recessedpart 14 f, etc., may be inserted into protruding part 132, etc.

With this configuration, first eye cup 14 and second eye cup 24 can beeasily connected and disconnected via engagement between a recessed andprotruded structure. Accordingly, changing out first eye cup 14 andsecond eye cup 24 is less complex. Accordingly, HMD 100 can be keptsanitary easily, is difficult to become insanitary, and is suitable foruse.

Moreover, for example, first protruding part 132 may further includefirst projecting part 133 that extends toward the inner surface of firstlens tube 10 and is spaced a given distance from the inner surface offirst lens tube 10, and the second protruding part may further include asecond projecting part that extends toward the inner surface of secondlens tube 20 and is spaced a given distance from the inner surface ofsecond lens tube 20.

With this configuration, since projecting parts provide engagement,first eye cup 14 and second eye cup 24 can be inhibited fromunintentionally falling off without affecting how easy it is to attachand remove first eye cup 14 and second eye cup 24. Accordingly, HMD 100can be kept sanitary easily, is difficult to become insanitary, and issuitable for use.

Moreover, for example, first lens tube 10 may further include therein:first support ring 127 disposed closer to the bottom than firstinsertion part 14 a is; and first correction lens 134 that is sandwichedby first insertion part 14 a and first support ring 127 and adjusts thefocal length of first convex lens 40L, and second lens tube 20 mayfurther include therein: a second support ring disposed closer to thebottom than a second insertion part is; and second correction lens 134that is sandwiched by the second insertion part and the second supportring and adjusts the focal length of second convex lens 40R.

With this configuration, it is possible to realize HMD 100 that issuitable for the eyesight of user 99 by using correction lenses 134.

Moreover, since the correction lenses 134 can be exchanged by theexchanging of first eye cup 14 and second eye cup 24, it is possible torealize a single HMD 100 that is suitable for a plurality of users 99.

Moreover, for example, first eye cup 14 and second eye cup 24 mayinclude: narrow part 14 c, etc., that is disposed between insertion part14 a, etc., and cup part 14 b, etc., and is formed around an entirecircumference of an outer surface first eye cup 14 and second eye cup24; and thick part 14 d, etc., formed to fill in a space defined bynarrow part 14 c, etc., at an intersection of a line and narrow part 14c, etc., the line being parallel to the arrangement direction of firstlens tube 10 and second lens tube 20 and passing through a center ofnarrow part 14 c, etc., in a height direction perpendicular to thearrangement direction.

With this configuration, first narrow part 14 c, the second narrow part,first thick part 14 d, and the second thick part give first eye cup 14and second eye cup 24 flexibility characterized in that the direction ofdeflection is controlled. Accordingly, the fit of HMD 100 is improved,and HMD 100 can properly display images.

Moreover, for example, first eye cup 14 may include, on the first cuppart 14 b end of first thick part 14 d, first plate part 14 e thatexpands horizontally relative to a plane intersecting the central axisof first lens tube 10, the outer circumference of first cup part 14 band the outer circumference of first plate part 14 e may be connected,and second eye cup 24 may include, on a second cup part end of a secondthick part, a second plate part that expands horizontally relative to aplane intersecting the central axis of second lens tube 20, and theouter circumference of the second cup part and the outer circumferenceof the second plate part may be connected.

With this configuration, first narrow part 14 c, the second narrow part,first thick part 14 d, the second thick part, first plate part 14 e, andthe second plate part give first eye cup 14 and second eye cup 24flexibility characterized in that the direction of deflection iscontrolled. Accordingly, the fit of HMD 100 is improved, and HMD 100 canproperly display images.

Moreover, for example, first thick part 14 d may have a tapered shapethat widens in diameter in a direction parallel to the central axis offirst lens tube 10 and toward the bottom of first lens tube 10, and thesecond thick part may have a tapered shape that widens in diameter in adirection parallel to the central axis of second lens tube 20 and towardthe bottom of second lens tube 20.

With this configuration, first narrow part 14 c, the second narrow part,first thick part 14 d, the second thick part, first plate part 14 e, andthe second plate part give first eye cup 14 and second eye cup 24flexibility characterized in that the direction of deflection iscontrolled using the tip end of the taper as a fulcrum. Accordingly, thefit of HMD 100 is improved, and HMD 100 can properly display images.

Moreover, for example, the hardness of the top side of each of first eyecup 14 and second eye cup 24 in the height direction perpendicular tothe arrangement plane including the central axis of first lens tube 10and the central axis of second lens tube 20 may be harder than thehardness of the bottom side of each of first eye cup 14 and second eyecup 24 in the height direction.

With this configuration, first lens tube 10 and second lens tube 20 canbe supported by the brow of user 99 mainly on the top side of each offirst eye cup 14 and second eye cup 24. Accordingly, the fit of HMD 100is improved, and HMD 100 can properly display images.

Moreover, for example, the material of the top sides of first eye cup 14and second eye cup 24 in the height direction may be different than thematerial of the bottom sides of first eye cup 14 and second eye cup 24in the height direction.

With this configuration, the difference in hardness is achieved via thedifference in material, and first lens tube 10 and second lens tube 20can be supported by the brow of user 99 mainly on the top side of eachof first eye cup 14 and second eye cup 24. Accordingly, the fit of HMD100 is improved, and HMD 100 can properly display images.

Moreover, for example, the surface area of contact of first eye cup 14and second eye cup 24 with the head of user 99 may be larger on the topsides than on the bottom sides in the height direction perpendicular tothe arrangement plane including the central axis of first lens tube 10and the central axis of second lens tube 20.

With this configuration, first lens tube 10 and second lens tube 20 canbe supported by the brow of user 99 mainly on the top side of each offirst eye cup 14 and second eye cup 24. Accordingly, the fit of HMD 100is improved, and HMD 100 can properly display images.

Moreover, for example, in a state in which first eye cup 14 and secondeye cup 24 are removed, HMD 100 may further include pad 136 that isinterposed between HMD 100 and the brow of user 99, is fittable to thetop portion of HMD 100 in the height direction perpendicular to thearrangement plane including the central axis of first lens tube 10 andthe central axis of second lens tube 20.

With this configuration, first lens tube 10 and second lens tube 20 canbe supported by pad 136 instead of by first eye cup 14 and second eyecup 24.

Moreover, for example, the first eye cup and the second eye cup may bemade using silicon rubber.

With this configuration, first eye cup 14 and second eye cup 24 madeusing silicon rubber can be interposed between the head of user 99 andfirst and second lens tubes 10 and 20, thereby making it possible tokeep first lens tube 10 and second lens tube 20 sanitary.

Moreover, for example, HMD 100 c may include: a closed-bottom first lenstube 10 including first display panel 39L on the closed bottom fordisplaying first image 101L; a closed-bottom second lens tube 20including second display panel 39R on the closed bottom for displayingsecond image 101R; a fourth adjustment mechanism including first rod 71that extends from first lens tube 10 and second rod 72 that extends fromsecond lens tube 20 and is rotatably connected relative to first rod 71;and an image angle maintainer that, in accordance with the angle ofrotation of first rod 71 and second rod 72 of the fourth adjustmentmechanism, rotates first display panel 39L relative to first lens tube10 and rotates second display panel 39R relative to second lens tube 20to bring the horizontal directions of first display panel 39L and seconddisplay panel 39R closer to the arrangement direction of first lens tube10 and second lens tube 20.

With this configuration, when second rod 72 is rotated relative to firstrod 71, the orientation of the displayed image can be maintained byrotating first display panel 39L and second display panel 39R.Accordingly, HMD 100 c can properly display images.

Moreover, for example, the image angle maintainer may include: stator111 that is provided on rotation shaft part 73 and does not rotate withfirst rod 71 and second rod 72; first rotor 112 that is coupled to firstdisplay panel 39L and rotates with first display panel 39L; first belt114 that rotates first rotor 112 by half the amount of rotation of firstrod 71 and second rod 72 relative to stator 111; second rotor 113 thatis coupled to second display panel 39R and rotates with second displaypanel 39R; and second belt 115 that rotates second rotor 113 by half theamount of rotation of first rod 71 and second rod 72 relative to stator111.

With this configuration, it is possible to maintain the orientation ofthe displayed image by rotating first display panel 39L and seconddisplay panel 39R via the rotation transferred by first belt 114 andsecond belt 115. Accordingly, HMD 100 c can properly display images.

Moreover, for example, the image angle maintainer may include: fixedgear 84 that is provided on rotation shaft part 73 and does not rotatewith first rod 71 and second rod 72; first rotary gear 85 that iscoupled to first display panel 39L and rotates with first display panel39L; and one or more first transfer gears 87 that rotate first rotarygear 85 by half the amount of rotation of first rod 71 and first rod 72relative to fixed gear 84; second rotary gear 86 that is coupled tosecond display panel 39R and rotates with second display panel 39R; andone or more second transfer gears 88 that rotate second rotary gear 86by half the amount of rotation of first rod 71 and second rod 72relative to fixed gear 84.

With this configuration, it is possible to maintain the orientation ofthe displayed image by rotating first display panel 39L and seconddisplay panel 39R via the rotation transferred by the one or more firsttransfer gears 87 and the one or more second transfer gears 88.Accordingly, HMD 100 c can properly display images.

Moreover, for example, the number of first transfer gears 87 and thenumber of second transfer gears 88 may be equal.

With this configuration, first transfer gear 87 and second transfer gear88 may share the same basic design, making it easier to realize theabove configuration. Accordingly, HMD 100 c can properly display images.

Moreover, for example, HMD 100 c that is worn on the head of user 99 mayinclude: a closed-bottom first lens tube 10 including therein firstdisplay panel 39L for displaying an image corresponding to one eye ofuser 99 and first convex lens 40L that enlarges the image displayed onfirst display panel 39L; a closed-bottom second lens tube 20 includingtherein second display panel 39R for displaying an image correspondingto the other eye of user 99 and second convex lens 40R that enlarges theimage displayed on second display panel 39R; and a fourth adjustmentmechanism that is capable of adjusting the distance between first lenstube 10 and second lens tube 20. First display panel 39L may be providedso as to be rotatable around the central axis of first lens tube 10.Second display panel 39R may be provided so as to be rotatable aroundthe central axis of second lens tube 20. The fourth adjustment mechanismmay include: first rod 71 having one end that is connected to first lenstube 10 and another end that extends in a direction away from first lenstube 10; second rod 72 that has one end connected to second lens tube 20and another end that extends in a direction away from second lens tube20; rotation shaft part 73 that rotatably connects first rod 71 andsecond rod 72; and an image angle maintainer that, in accordance withthe angle of rotation of first rod 71 and second rod 72, rotates firstdisplay panel 39L relative to first lens tube 10 and rotates seconddisplay panel 39R relative to second lens tube 20 in a directionopposite that of the direction of rotation of first display panel 39L.The image angle maintainer may include expandable rod 83 including innertube 82 that is inserted in outer tube 81 and expands and collapses inan expansion direction in outer tube 81. Expandable rod 83 may connectfirst display panel 39L to the outer tube 81 side end so as to fix theangle of first display panel 39L relative to the expanding axis, andconnect second display panel 39R to the inner tube 82 side end so as tofix the angle of second display panel 39R relative to the expandingaxis.

With this configuration, expandable rod 83 can cancel the rotation offirst display panel 39L and second display panel 39R that accompaniesthe rotational movement of other parts and thus maintain the orientationof images displayed on first display panel 39L and second display panel39R. Accordingly, HMD 100 c can properly display images.

Moreover, for example, HMD 100 c may further include a nose piece partincluding nose pad 152 that contacts nasal root 97 of user 99 wearingHMD 100 c, mounting part 151 mounted to expandable rod 83, and acoupling part that couples nose pad 152 and mounting part 151 at a givendistance and a given angle. The coupling part may be made using amaterial capable of deformation by an outside force.

With this configuration, it is possible to support HMD 100 c with nasalroot 97 as well, thereby further stabilizing the orientation of HMD 100c. Accordingly, wobbling of HMD 100 c can be inhibited, and HMD 100 canproperly display images.

Moreover, for example, HMD 100 c may further include a nose piece partincluding nose pad 152 that contacts nasal root 97 of user 99 wearingHMD 100 c, mounting part 151 mounted to expandable rod 83, and acoupling part that couples nose pad 152 and mounting part 151 at a givendistance and a given angle. The coupling part may include platecomponent 153 that is coupled to mounting part 151 and includes couplinghole 153 a, rod component 154 that has a leading end coupled to nose pad152 and is inserted through coupling hole 153 a; and fixing component155 that fixes the length of rod component 154 that is inserted intocoupling hole 153 a.

With this configuration, it is possible to support HMD 100 c with nasalroot 97 as well, thereby further stabilizing the orientation of HMD 100c. Accordingly, wobbling of HMD 100 c can be inhibited, and HMD 100 canproperly display images.

Moreover, for example, HMD 100 may further include image outputter 38 bthat adjusts display positions of images to be displayed on firstdisplay panel 39L and second display panel 39R. Image outputter 38 b mayadjust the position of the image to be displayed on second display panel39R so as to be symmetrical about the height direction perpendicular tothe arrangement direction of first lens tube and second lens tube 20 andantisymmetrical about the arrangement direction relative to the centerof second display panel 39R, in accordance with the position of theimage to be displayed on first display panel 39L relative to the centerof first display panel 39L.

With this configuration, it is possible to adjust the display positionsof images based on the positions of both eyes of user 99.

Accordingly, HMD 100 c can properly display images.

Moreover, for example, image outputter 38 b may perform distortioncorrection processing of correcting the lens distortion of first convexlens 40L according to the position of the image to be displayed on firstdisplay panel 39L relative to the center of first display panel 39L andcorrecting the lens distortion of second convex lens 40R according tothe position of the image to be displayed on second display panel 39Rrelative to the center of second display panel 39R.

This configuration allows HMD 100 c to properly display imagesregardless of lens distortion.

Moreover, for example, focal correction corresponding to the eyesight ofuser 99 may be performed by adjusting the distance between first convexlens 40L and first display panel 39L and adjusting the distance betweensecond convex lens 40R and second display panel 39R, and image outputter38 b may perform zoom processing of changing the display size of theimage to be displayed on first display panel 39L and the image to bedisplayed on second display panel 39R in accordance with the focalcorrection.

This configuration allows HMD 100 c to properly display imagesregardless of changes in angle of view resulting from optical systemadjustments.

Moreover, for example, in accordance with the angle of rotation of firstrod 71 and second rod 72, image outputter 38 b may: (1) perform a firstprocess of displaying, as first image 101L to be displayed on firstdisplay panel 39L, first rotated image 102L generated by changing thedisplay angle of first image 101L; and (2) perform a second process ofdisplaying, as second image 101R to be displayed on second display panel39R, second rotated image 102R generated by changing the display angleof second image 101R.

With this configuration, when second rod 72 is rotated relative to firstrod 71, first rotated image 102L and second rotated image 102R aregenerated by rotating the images displayed by first display panel 39Land second display panel 39R. The orientation of the images from theviewpoint of user 99 can be maintained by displaying first rotated image102L and second rotated image 102R on first display panel 39L and seconddisplay panel 39R, respectively. Accordingly, HMD 100 c can properlydisplay images.

Moreover, for example, the fourth adjustment mechanism may include anangle detector that detects the angle of rotation of first rod 71 andsecond rod 72, and the image outputter may perform at least one of thefirst process and the second process based on the angle of rotation offirst rod 71 and second rod 72 detected by the angle detector.

With this configuration, when second rod 72 is rotated relative to firstrod 71, the orientation of the images from the perspective of user 99can be maintained by rotating the images displayed by first displaypanel 39L and second display panel 39R in accordance with the detectedangle of rotation. Accordingly, HMD 100 c can properly display images.

Moreover, for example, the angle detector may detect the angle ofrotation of first rod 71 and second rod 72 by estimating the angle ofrotation based on a measured resistance value of resistance element 116provided on the axis of rotation of first rod 71 and second rod 72. Theresistance value of resistance element 116 changes in accordance withthe angle of rotation of first rod 71 and second rod 72.

With this configuration, when second rod 72 is rotated relative to firstrod 71, the angle of rotation can be detected using the resistance valuemeasured in resistance element 116. With this configuration, theorientation of the images from the perspective of user 99 can bemaintained by rotating the images displayed by first display panel 39Land second display panel 39R in accordance with the detected angle ofrotation. Accordingly, HMD 100 c can properly display images.

Moreover, for example, the angle detector may calculate first angledifference 83 relative to a reference orientation in first gyrosensor117 provided in or on first lens tube 10, calculate second angledifference 84 relative to a reference orientation in second gyrosensor118 provided in or on second lens tube 20, and detect the sum of theabsolute value of first angle difference 83 and second angle difference84 as the angle of rotation of first rod 71 and second rod 72.

With this configuration, when second rod 72 is rotated relative to firstrod 71, it is possible to detect the angle of rotation from angledifferences 83 and 84 relative to a reference orientation calculatedusing first gyrosensor 117 and second gyrosensor 118. With thisconfiguration, the orientation of the images from the perspective ofuser 99 can be maintained by rotating the images displayed by firstdisplay panel 39L and second display panel 39R in accordance with thedetected angle of rotation. Accordingly, HMD 100 c can properly displayimages.

Moreover, for example, at least one of first lens tube 10 and secondlens tube 20 may further include measurement device 121 or 122 thatmeasures the distance between first lens tube 10 and second lens tube20, and angle detector may detect the angle of rotation of first rod 71and second rod 72 using the length from the axis of rotation of firstrod 71 and second rod 72 to first lens tube 10 or second lens tube 20and the distance between first lens tube 10 and second lens tube 20measured by measurement device 121 or 122.

With this configuration, when second rod 72 is rotated relative to firstrod 71, it is possible to detect the angle of rotation with, forexample, a sine function, using the distance between first lens tube 10and second lens tube 20 measured using measurement device 121 or 122.With this configuration, the orientation of the images from theperspective of user 99 can be maintained by rotating the imagesdisplayed by first display panel 39L and second display panel 39R inaccordance with the detected angle of rotation. Accordingly, HMD 100 ccan properly display images.

Moreover, for example, in the first process, first rotated image 102Lmay be generated by rotating first image 101L by an angle half the angleof rotation of first rod 71 and second rod 72 detected by the angledetector and in a direction opposite the direction of rotation of firstrod 71, and in the second process second rotated image 102R may begenerated by rotating second image 101R by an angle half the angle ofrotation of first rod 71 and second rod 72 detected by the angledetector and in a direction opposite the direction of rotation of secondrod 72.

With this configuration, first rotated image 102L rotated half theamount of rotation is generated via the first process, and secondrotated image 102R rotated half the amount of the angle of rotation isgenerated via the second process. First rotated image 102L is rotated inone direction relative to the original image, and second rotated image102R is rotated in the other direction relative to the original image.The orientation of the images from the viewpoint of user 99 can bemaintained by displaying first rotated image 102L and second rotatedimage 102R generated in this manner on first display panel 39L andsecond display panel 39R, respectively. Accordingly, HMD 100 c canproperly display images.

Moreover, for example, first lens tube 10 may include first camera 123Lthat is provided on the bottom of first lens tube 10 and captures imagesin a direction parallel to the central axis of first lens tube 10 andopposite the direction toward the opening of first lens tube 10, secondlens tube 20 may include second camera 123R that is provided on thebottom of second lens tube 20 and captures images in a directionparallel to the central axis of second lens tube 20 and opposite thedirection toward the opening of second lens tube 20, and image outputter38 b may rotate the images captured by first camera 123L and secondcamera 123R in accordance with the angle of rotation of first rod 71 andsecond rod 72 detected by the angle detector.

With this configuration, when first lens tube 10 and second lens tube 20of HMD 100 c are provided with first camera 123L and second camera 123R,respectively, the orientations of images captured by first camera 123Land second camera 123R can be properly maintained regardless of theangle of rotation. Accordingly, HMD 100 c properly displays images whenimages that are captured by first camera 123L and second camera 123R andproperly maintained are displayed.

Moreover, for example, HMD 100 may include first camera 123L thatcaptures images in a direction parallel to the central axis of firstlens tube 10 and opposite the direction toward the opening of first lenstube 10, second camera 123R that captures images in a direction parallelto the central axis of second lens tube 20 and opposite the directiontoward the opening of second lens tube 20, and a camera holdingmechanism that holds first camera 123L and second camera so as tomaintain a given distance between first camera 123L and second camera123R.

With this configuration, the camera holding mechanism properly maintainsthe parallax between the images captured by first camera 123L and secondcamera 123R regardless of the angle of rotation. Accordingly, HMD 100 cproperly displays images when displaying three-dimensional images usingimages captured by first camera 123L and second camera 123R. HMD 100 ccan perform proper measurement when measuring the distance to an objectusing images captured by first camera 123L and second camera 123R.

Moreover, for example, image outputter 38 b may adjust the position ofthe image to be displayed on second display panel 39R so as to besymmetrical about the height direction perpendicular to the arrangementdirection of first lens tube 10 and second lens tube 20 andantisymmetrical about the arrangement direction relative to the centerof second display panel 39R, in accordance with the position of theimage to be displayed on first display panel 39L relative to the centerof first display panel 39L.

With this configuration, it is possible to adjust the display positionsof images based on the positions of both eyes of user 99. Accordingly,HMD 100 c can properly display images.

Moreover, for example, image outputter 38 b may perform distortioncorrection processing of correcting the lens distortion of first convexlens 40L according to the position of the image to be displayed on firstdisplay panel 39L relative to the center of first display panel 39L andcorrecting the lens distortion of second convex lens 40R according tothe position of the image to be displayed on second display panel 39Rrelative to the center of second display panel 39R.

This configuration allows HMD 100 c to properly display imagesregardless of lens distortion.

Moreover, for example, focal correction corresponding to the eyesight ofuser 99 may be performed by adjusting the distance between first convexlens 40L and first display panel 39L and adjusting the distance betweensecond convex lens 40R and second display panel 39R, and image outputter38 b may perform zoom processing of changing the display size of theimage to be displayed on first display panel 39L and the image to bedisplayed on second display panel 39R in accordance with the focalcorrection.

This configuration allows HMD 100 c to properly display imagesregardless of changes in angle of view resulting from optical systemadjustments.

Other Embodiments

Although embodiments have been described above, the present disclosureis not limited to the above embodiments.

Although the elements included in the HMD have been described in theabove embodiments, the functions performed by the elements included inthe HMD may be divided between various parts of the HMD in any manner.

Those skilled in the art will readily appreciate that variousmodifications may be made in these embodiments and that otherembodiments may be obtained by arbitrarily combining the elements andfunctions of the embodiments without materially departing from the novelteachings and advantages of the present disclosure. Accordingly, allsuch modifications and other embodiments are included in the presentdisclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable as a wearable display device suchas a head-mounted display.

1. A display device, comprising: a first lens tube including a closedbottom and a first display part on the closed bottom, the first displaypart being for displaying a first image; a second lens tube including aclosed bottom and a second display part on the closed bottom, the seconddisplay part being for displaying a second image; an adjustmentmechanism including a first rod that extends from the first lens tubeand a second rod that extends from the second lens tube and is rotatablyconnected to the first rod; and an image outputter that outputs thefirst image and the second image to the first display part and thesecond display part, respectively, wherein the image outputter, inaccordance with an angle of rotation of the first rod and the second rodof the adjustment mechanism, controls and outputs the first image andthe second image to bring horizontal directions of the first image andthe second image closer to an arrangement direction of the first lenstube and the second lens tube.
 2. The display device according to claim1, wherein, in accordance with the angle of rotation of the first rodand the second rod, the image outputter: (1) performs a first process ofdisplaying, as the first image to be displayed on the first displaypart, a first rotated image generated by changing a display angle of thefirst image; and (2) performs a second process of displaying, as thesecond image to be displayed on the second display part, a secondrotated image generated by changing a display angle of the second image.3. The display device according to claim 2, wherein the adjustmentmechanism includes an angle detector that detects the angle of rotationof the first rod and the second rod, and the image outputter performs atleast one of the first process and the second process based on the angleof rotation of the first rod and the second rod detected by the angledetector.
 4. The display device according to claim 3, wherein the angledetector detects the angle of rotation of the first rod and the secondrod by estimating the angle of rotation based on a measured resistancevalue of a resistance element provided on an axis of rotation, whereinthe resistance value of the resistance element changes in accordancewith the angle of rotation of the first rod and the second rod.